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Diffstat (limited to 'gfx/wr/webrender/src/picture.rs')
| -rw-r--r-- | gfx/wr/webrender/src/picture.rs | 7199 |
1 files changed, 7199 insertions, 0 deletions
diff --git a/gfx/wr/webrender/src/picture.rs b/gfx/wr/webrender/src/picture.rs new file mode 100644 index 0000000000..5b1a232deb --- /dev/null +++ b/gfx/wr/webrender/src/picture.rs @@ -0,0 +1,7199 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +//! A picture represents a dynamically rendered image. +//! +//! # Overview +//! +//! Pictures consists of: +//! +//! - A number of primitives that are drawn onto the picture. +//! - A composite operation describing how to composite this +//! picture into its parent. +//! - A configuration describing how to draw the primitives on +//! this picture (e.g. in screen space or local space). +//! +//! The tree of pictures are generated during scene building. +//! +//! Depending on their composite operations pictures can be rendered into +//! intermediate targets or folded into their parent picture. +//! +//! ## Picture caching +//! +//! Pictures can be cached to reduce the amount of rasterization happening per +//! frame. +//! +//! When picture caching is enabled, the scene is cut into a small number of slices, +//! typically: +//! +//! - content slice +//! - UI slice +//! - background UI slice which is hidden by the other two slices most of the time. +//! +//! Each of these slice is made up of fixed-size large tiles of 2048x512 pixels +//! (or 128x128 for the UI slice). +//! +//! Tiles can be either cached rasterized content into a texture or "clear tiles" +//! that contain only a solid color rectangle rendered directly during the composite +//! pass. +//! +//! ## Invalidation +//! +//! Each tile keeps track of the elements that affect it, which can be: +//! +//! - primitives +//! - clips +//! - image keys +//! - opacity bindings +//! - transforms +//! +//! These dependency lists are built each frame and compared to the previous frame to +//! see if the tile changed. +//! +//! The tile's primitive dependency information is organized in a quadtree, each node +//! storing an index buffer of tile primitive dependencies. +//! +//! The union of the invalidated leaves of each quadtree produces a per-tile dirty rect +//! which defines the scissor rect used when replaying the tile's drawing commands and +//! can be used for partial present. +//! +//! ## Display List shape +//! +//! WR will first look for an iframe item in the root stacking context to apply +//! picture caching to. If that's not found, it will apply to the entire root +//! stacking context of the display list. Apart from that, the format of the +//! display list is not important to picture caching. Each time a new scroll root +//! is encountered, a new picture cache slice will be created. If the display +//! list contains more than some arbitrary number of slices (currently 8), the +//! content will all be squashed into a single slice, in order to save GPU memory +//! and compositing performance. +//! +//! ## Compositor Surfaces +//! +//! Sometimes, a primitive would prefer to exist as a native compositor surface. +//! This allows a large and/or regularly changing primitive (such as a video, or +//! webgl canvas) to be updated each frame without invalidating the content of +//! tiles, and can provide a significant performance win and battery saving. +//! +//! Since drawing a primitive as a compositor surface alters the ordering of +//! primitives in a tile, we use 'overlay tiles' to ensure correctness. If a +//! tile has a compositor surface, _and_ that tile has primitives that overlap +//! the compositor surface rect, the tile switches to be drawn in alpha mode. +//! +//! We rely on only promoting compositor surfaces that are opaque primitives. +//! With this assumption, the tile(s) that intersect the compositor surface get +//! a 'cutout' in the rectangle where the compositor surface exists (not the +//! entire tile), allowing that tile to be drawn as an alpha tile after the +//! compositor surface. +//! +//! Tiles are only drawn in overlay mode if there is content that exists on top +//! of the compositor surface. Otherwise, we can draw the tiles in the normal fast +//! path before the compositor surface is drawn. Use of the per-tile valid and +//! dirty rects ensure that we do a minimal amount of per-pixel work here to +//! blend the overlay tile (this is not always optimal right now, but will be +//! improved as a follow up). + +use api::{MixBlendMode, PremultipliedColorF, FilterPrimitiveKind}; +use api::{PropertyBinding, PropertyBindingId, FilterPrimitive, RasterSpace}; +use api::{DebugFlags, ImageKey, ColorF, ColorU, PrimitiveFlags}; +use api::{ImageRendering, ColorDepth, YuvRangedColorSpace, YuvFormat, AlphaType}; +use api::units::*; +use crate::command_buffer::PrimitiveCommand; +use crate::box_shadow::BLUR_SAMPLE_SCALE; +use crate::clip::{ClipStore, ClipChainInstance, ClipLeafId, ClipNodeId, ClipTreeBuilder}; +use crate::spatial_tree::{SpatialTree, CoordinateSpaceMapping, SpatialNodeIndex, VisibleFace}; +use crate::composite::{CompositorKind, CompositeState, NativeSurfaceId, NativeTileId, CompositeTileSurface, tile_kind}; +use crate::composite::{ExternalSurfaceDescriptor, ExternalSurfaceDependency, CompositeTileDescriptor, CompositeTile}; +use crate::composite::{CompositorTransformIndex}; +use crate::debug_colors; +use euclid::{vec3, Point2D, Scale, Vector2D, Box2D}; +use euclid::approxeq::ApproxEq; +use crate::filterdata::SFilterData; +use crate::intern::ItemUid; +use crate::internal_types::{FastHashMap, FastHashSet, PlaneSplitter, Filter, FrameId}; +use crate::internal_types::{PlaneSplitterIndex, PlaneSplitAnchor, TextureSource}; +use crate::frame_builder::{FrameBuildingContext, FrameBuildingState, PictureState, PictureContext}; +use crate::gpu_cache::{GpuCache, GpuCacheAddress, GpuCacheHandle}; +use crate::gpu_types::{UvRectKind, ZBufferId}; +use peek_poke::{PeekPoke, poke_into_vec, peek_from_slice, ensure_red_zone}; +use plane_split::{Clipper, Polygon}; +use crate::prim_store::{PrimitiveTemplateKind, PictureIndex, PrimitiveInstance, PrimitiveInstanceKind}; +use crate::prim_store::{ColorBindingStorage, ColorBindingIndex, PrimitiveScratchBuffer}; +use crate::print_tree::{PrintTree, PrintTreePrinter}; +use crate::render_backend::DataStores; +use crate::render_task_graph::RenderTaskId; +use crate::render_target::RenderTargetKind; +use crate::render_task::{BlurTask, RenderTask, RenderTaskLocation, BlurTaskCache}; +use crate::render_task::{StaticRenderTaskSurface, RenderTaskKind}; +use crate::renderer::BlendMode; +use crate::resource_cache::{ResourceCache, ImageGeneration, ImageRequest}; +use crate::space::SpaceMapper; +use crate::scene::SceneProperties; +use crate::spatial_tree::CoordinateSystemId; +use crate::surface::{SurfaceDescriptor, SurfaceTileDescriptor}; +use smallvec::SmallVec; +use std::{mem, u8, marker, u32}; +use std::sync::atomic::{AtomicUsize, Ordering}; +use std::collections::hash_map::Entry; +use std::ops::Range; +use crate::picture_textures::PictureCacheTextureHandle; +use crate::util::{MaxRect, VecHelper, MatrixHelpers, Recycler, ScaleOffset}; +use crate::filterdata::{FilterDataHandle}; +use crate::tile_cache::{SliceDebugInfo, TileDebugInfo, DirtyTileDebugInfo}; +use crate::visibility::{PrimitiveVisibilityFlags, FrameVisibilityContext}; +use crate::visibility::{VisibilityState, FrameVisibilityState}; +use crate::scene_building::{SliceFlags}; + +// Maximum blur radius for blur filter (different than box-shadow blur). +// Taken from FilterNodeSoftware.cpp in Gecko. +const MAX_BLUR_RADIUS: f32 = 100.; + +/// Specify whether a surface allows subpixel AA text rendering. +#[derive(Debug, Copy, Clone)] +pub enum SubpixelMode { + /// This surface allows subpixel AA text + Allow, + /// Subpixel AA text cannot be drawn on this surface + Deny, + /// Subpixel AA can be drawn on this surface, if not intersecting + /// with the excluded regions, and inside the allowed rect. + Conditional { + allowed_rect: PictureRect, + }, +} + +/// A comparable transform matrix, that compares with epsilon checks. +#[derive(Debug, Clone)] +struct MatrixKey { + m: [f32; 16], +} + +impl PartialEq for MatrixKey { + fn eq(&self, other: &Self) -> bool { + const EPSILON: f32 = 0.001; + + // TODO(gw): It's possible that we may need to adjust the epsilon + // to be tighter on most of the matrix, except the + // translation parts? + for (i, j) in self.m.iter().zip(other.m.iter()) { + if !i.approx_eq_eps(j, &EPSILON) { + return false; + } + } + + true + } +} + +/// A comparable scale-offset, that compares with epsilon checks. +#[derive(Debug, Clone)] +struct ScaleOffsetKey { + sx: f32, + sy: f32, + tx: f32, + ty: f32, +} + +impl PartialEq for ScaleOffsetKey { + fn eq(&self, other: &Self) -> bool { + const EPSILON: f32 = 0.001; + + self.sx.approx_eq_eps(&other.sx, &EPSILON) && + self.sy.approx_eq_eps(&other.sy, &EPSILON) && + self.tx.approx_eq_eps(&other.tx, &EPSILON) && + self.ty.approx_eq_eps(&other.ty, &EPSILON) + } +} + +/// A comparable / hashable version of a coordinate space mapping. Used to determine +/// if a transform dependency for a tile has changed. +#[derive(Debug, PartialEq, Clone)] +enum TransformKey { + Local, + ScaleOffset { + so: ScaleOffsetKey, + }, + Transform { + m: MatrixKey, + } +} + +impl<Src, Dst> From<CoordinateSpaceMapping<Src, Dst>> for TransformKey { + fn from(transform: CoordinateSpaceMapping<Src, Dst>) -> TransformKey { + match transform { + CoordinateSpaceMapping::Local => { + TransformKey::Local + } + CoordinateSpaceMapping::ScaleOffset(ref scale_offset) => { + TransformKey::ScaleOffset { + so: ScaleOffsetKey { + sx: scale_offset.scale.x, + sy: scale_offset.scale.y, + tx: scale_offset.offset.x, + ty: scale_offset.offset.y, + } + } + } + CoordinateSpaceMapping::Transform(ref m) => { + TransformKey::Transform { + m: MatrixKey { + m: m.to_array(), + }, + } + } + } + } +} + +/// Unit for tile coordinates. +#[derive(Hash, Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd)] +pub struct TileCoordinate; + +// Geometry types for tile coordinates. +pub type TileOffset = Point2D<i32, TileCoordinate>; +pub type TileRect = Box2D<i32, TileCoordinate>; + +/// The maximum number of compositor surfaces that are allowed per picture cache. This +/// is an arbitrary number that should be enough for common cases, but low enough to +/// prevent performance and memory usage drastically degrading in pathological cases. +pub const MAX_COMPOSITOR_SURFACES: usize = 4; + +/// The size in device pixels of a normal cached tile. +pub const TILE_SIZE_DEFAULT: DeviceIntSize = DeviceIntSize { + width: 1024, + height: 512, + _unit: marker::PhantomData, +}; + +/// The size in device pixels of a tile for horizontal scroll bars +pub const TILE_SIZE_SCROLLBAR_HORIZONTAL: DeviceIntSize = DeviceIntSize { + width: 1024, + height: 32, + _unit: marker::PhantomData, +}; + +/// The size in device pixels of a tile for vertical scroll bars +pub const TILE_SIZE_SCROLLBAR_VERTICAL: DeviceIntSize = DeviceIntSize { + width: 32, + height: 1024, + _unit: marker::PhantomData, +}; + +/// The maximum size per axis of a surface, +/// in WorldPixel coordinates. +const MAX_SURFACE_SIZE: usize = 4096; +/// Maximum size of a compositor surface. +const MAX_COMPOSITOR_SURFACES_SIZE: f32 = 8192.0; + +/// Used to get unique tile IDs, even when the tile cache is +/// destroyed between display lists / scenes. +static NEXT_TILE_ID: AtomicUsize = AtomicUsize::new(0); + +fn clamp(value: i32, low: i32, high: i32) -> i32 { + value.max(low).min(high) +} + +fn clampf(value: f32, low: f32, high: f32) -> f32 { + value.max(low).min(high) +} + +/// An index into the prims array in a TileDescriptor. +#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub struct PrimitiveDependencyIndex(pub u32); + +/// Information about the state of a binding. +#[derive(Debug)] +pub struct BindingInfo<T> { + /// The current value retrieved from dynamic scene properties. + value: T, + /// True if it was changed (or is new) since the last frame build. + changed: bool, +} + +/// Information stored in a tile descriptor for a binding. +#[derive(Debug, PartialEq, Clone, Copy, PeekPoke)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub enum Binding<T> { + Value(T), + Binding(PropertyBindingId), +} + +impl<T: Default> Default for Binding<T> { + fn default() -> Self { + Binding::Value(T::default()) + } +} + +impl<T> From<PropertyBinding<T>> for Binding<T> { + fn from(binding: PropertyBinding<T>) -> Binding<T> { + match binding { + PropertyBinding::Binding(key, _) => Binding::Binding(key.id), + PropertyBinding::Value(value) => Binding::Value(value), + } + } +} + +pub type OpacityBinding = Binding<f32>; +pub type OpacityBindingInfo = BindingInfo<f32>; + +pub type ColorBinding = Binding<ColorU>; +pub type ColorBindingInfo = BindingInfo<ColorU>; + +#[derive(PeekPoke)] +enum PrimitiveDependency { + OpacityBinding { + binding: OpacityBinding, + }, + ColorBinding { + binding: ColorBinding, + }, + SpatialNode { + index: SpatialNodeIndex, + }, + Clip { + clip: ItemUid, + }, + Image { + image: ImageDependency, + }, +} + +/// A dependency for a transform is defined by the spatial node index + frame it was used +#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash, PeekPoke, Default)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub struct SpatialNodeKey { + spatial_node_index: SpatialNodeIndex, + frame_id: FrameId, +} + +/// A helper for comparing spatial nodes between frames. The comparisons +/// are done by-value, so that if the shape of the spatial node tree +/// changes, invalidations aren't done simply due to the spatial node +/// index changing between display lists. +struct SpatialNodeComparer { + /// The root spatial node index of the tile cache + ref_spatial_node_index: SpatialNodeIndex, + /// Maintains a map of currently active transform keys + spatial_nodes: FastHashMap<SpatialNodeKey, TransformKey>, + /// A cache of recent comparisons between prev and current spatial nodes + compare_cache: FastHashMap<(SpatialNodeKey, SpatialNodeKey), bool>, + /// A set of frames that we need to retain spatial node entries for + referenced_frames: FastHashSet<FrameId>, +} + +impl SpatialNodeComparer { + /// Construct a new comparer + fn new() -> Self { + SpatialNodeComparer { + ref_spatial_node_index: SpatialNodeIndex::INVALID, + spatial_nodes: FastHashMap::default(), + compare_cache: FastHashMap::default(), + referenced_frames: FastHashSet::default(), + } + } + + /// Advance to the next frame + fn next_frame( + &mut self, + ref_spatial_node_index: SpatialNodeIndex, + ) { + // Drop any node information for unreferenced frames, to ensure that the + // hashmap doesn't grow indefinitely! + let referenced_frames = &self.referenced_frames; + self.spatial_nodes.retain(|key, _| { + referenced_frames.contains(&key.frame_id) + }); + + // Update the root spatial node for this comparer + self.ref_spatial_node_index = ref_spatial_node_index; + self.compare_cache.clear(); + self.referenced_frames.clear(); + } + + /// Register a transform that is used, and build the transform key for it if new. + fn register_used_transform( + &mut self, + spatial_node_index: SpatialNodeIndex, + frame_id: FrameId, + spatial_tree: &SpatialTree, + ) { + let key = SpatialNodeKey { + spatial_node_index, + frame_id, + }; + + if let Entry::Vacant(entry) = self.spatial_nodes.entry(key) { + entry.insert( + get_transform_key( + spatial_node_index, + self.ref_spatial_node_index, + spatial_tree, + ) + ); + } + } + + /// Return true if the transforms for two given spatial nodes are considered equivalent + fn are_transforms_equivalent( + &mut self, + prev_spatial_node_key: &SpatialNodeKey, + curr_spatial_node_key: &SpatialNodeKey, + ) -> bool { + let key = (*prev_spatial_node_key, *curr_spatial_node_key); + let spatial_nodes = &self.spatial_nodes; + + *self.compare_cache + .entry(key) + .or_insert_with(|| { + let prev = &spatial_nodes[&prev_spatial_node_key]; + let curr = &spatial_nodes[&curr_spatial_node_key]; + curr == prev + }) + } + + /// Ensure that the comparer won't GC any nodes for a given frame id + fn retain_for_frame(&mut self, frame_id: FrameId) { + self.referenced_frames.insert(frame_id); + } +} + +// Immutable context passed to picture cache tiles during pre_update +struct TilePreUpdateContext { + /// Maps from picture cache coords -> world space coords. + pic_to_world_mapper: SpaceMapper<PicturePixel, WorldPixel>, + + /// The optional background color of the picture cache instance + background_color: Option<ColorF>, + + /// The visible part of the screen in world coords. + global_screen_world_rect: WorldRect, + + /// Current size of tiles in picture units. + tile_size: PictureSize, + + /// The current frame id for this picture cache + frame_id: FrameId, +} + +// Immutable context passed to picture cache tiles during update_dirty_and_valid_rects +struct TileUpdateDirtyContext<'a> { + /// Maps from picture cache coords -> world space coords. + pic_to_world_mapper: SpaceMapper<PicturePixel, WorldPixel>, + + /// Global scale factor from world -> device pixels. + global_device_pixel_scale: DevicePixelScale, + + /// Information about opacity bindings from the picture cache. + opacity_bindings: &'a FastHashMap<PropertyBindingId, OpacityBindingInfo>, + + /// Information about color bindings from the picture cache. + color_bindings: &'a FastHashMap<PropertyBindingId, ColorBindingInfo>, + + /// The local rect of the overall picture cache + local_rect: PictureRect, + + /// If true, the scale factor of the root transform for this picture + /// cache changed, so we need to invalidate the tile and re-render. + invalidate_all: bool, +} + +// Mutable state passed to picture cache tiles during update_dirty_and_valid_rects +struct TileUpdateDirtyState<'a> { + /// Allow access to the texture cache for requesting tiles + resource_cache: &'a mut ResourceCache, + + /// Current configuration and setup for compositing all the picture cache tiles in renderer. + composite_state: &'a mut CompositeState, + + /// A cache of comparison results to avoid re-computation during invalidation. + compare_cache: &'a mut FastHashMap<PrimitiveComparisonKey, PrimitiveCompareResult>, + + /// Information about transform node differences from last frame. + spatial_node_comparer: &'a mut SpatialNodeComparer, +} + +// Immutable context passed to picture cache tiles during post_update +struct TilePostUpdateContext { + /// The local clip rect (in picture space) of the entire picture cache + local_clip_rect: PictureRect, + + /// The calculated backdrop information for this cache instance. + backdrop: Option<BackdropInfo>, + + /// Current size in device pixels of tiles for this cache + current_tile_size: DeviceIntSize, + + /// Pre-allocated z-id to assign to tiles during post_update. + z_id: ZBufferId, +} + +// Mutable state passed to picture cache tiles during post_update +struct TilePostUpdateState<'a> { + /// Allow access to the texture cache for requesting tiles + resource_cache: &'a mut ResourceCache, + + /// Current configuration and setup for compositing all the picture cache tiles in renderer. + composite_state: &'a mut CompositeState, +} + +/// Information about the dependencies of a single primitive instance. +struct PrimitiveDependencyInfo { + /// Unique content identifier of the primitive. + prim_uid: ItemUid, + + /// The (conservative) clipped area in picture space this primitive occupies. + prim_clip_box: PictureBox2D, + + /// Image keys this primitive depends on. + images: SmallVec<[ImageDependency; 8]>, + + /// Opacity bindings this primitive depends on. + opacity_bindings: SmallVec<[OpacityBinding; 4]>, + + /// Color binding this primitive depends on. + color_binding: Option<ColorBinding>, + + /// Clips that this primitive depends on. + clips: SmallVec<[ItemUid; 8]>, + + /// Spatial nodes references by the clip dependencies of this primitive. + spatial_nodes: SmallVec<[SpatialNodeIndex; 4]>, +} + +impl PrimitiveDependencyInfo { + /// Construct dependency info for a new primitive. + fn new( + prim_uid: ItemUid, + prim_clip_box: PictureBox2D, + ) -> Self { + PrimitiveDependencyInfo { + prim_uid, + images: SmallVec::new(), + opacity_bindings: SmallVec::new(), + color_binding: None, + prim_clip_box, + clips: SmallVec::new(), + spatial_nodes: SmallVec::new(), + } + } +} + +/// A stable ID for a given tile, to help debugging. These are also used +/// as unique identifiers for tile surfaces when using a native compositor. +#[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Ord, Eq)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub struct TileId(pub usize); + +/// Uniquely identifies a tile within a picture cache slice +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +#[derive(Debug, Copy, Clone, PartialEq, Hash, Eq)] +pub struct TileKey { + // Tile index (x,y) + pub tile_offset: TileOffset, + // Sub-slice (z) + pub sub_slice_index: SubSliceIndex, +} + +/// A descriptor for the kind of texture that a picture cache tile will +/// be drawn into. +#[derive(Debug)] +pub enum SurfaceTextureDescriptor { + /// When using the WR compositor, the tile is drawn into an entry + /// in the WR texture cache. + TextureCache { + handle: Option<PictureCacheTextureHandle>, + }, + /// When using an OS compositor, the tile is drawn into a native + /// surface identified by arbitrary id. + Native { + /// The arbitrary id of this tile. + id: Option<NativeTileId>, + }, +} + +/// This is the same as a `SurfaceTextureDescriptor` but has been resolved +/// into a texture cache handle (if appropriate) that can be used by the +/// batching and compositing code in the renderer. +#[derive(Clone, Debug, Eq, PartialEq, Hash)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub enum ResolvedSurfaceTexture { + TextureCache { + /// The texture ID to draw to. + texture: TextureSource, + }, + Native { + /// The arbitrary id of this tile. + id: NativeTileId, + /// The size of the tile in device pixels. + size: DeviceIntSize, + } +} + +impl SurfaceTextureDescriptor { + /// Create a resolved surface texture for this descriptor + pub fn resolve( + &self, + resource_cache: &ResourceCache, + size: DeviceIntSize, + ) -> ResolvedSurfaceTexture { + match self { + SurfaceTextureDescriptor::TextureCache { handle } => { + let texture = resource_cache + .picture_textures + .get_texture_source(handle.as_ref().unwrap()); + + ResolvedSurfaceTexture::TextureCache { texture } + } + SurfaceTextureDescriptor::Native { id } => { + ResolvedSurfaceTexture::Native { + id: id.expect("bug: native surface not allocated"), + size, + } + } + } + } +} + +/// The backing surface for this tile. +#[derive(Debug)] +pub enum TileSurface { + Texture { + /// Descriptor for the surface that this tile draws into. + descriptor: SurfaceTextureDescriptor, + }, + Color { + color: ColorF, + }, + Clear, +} + +impl TileSurface { + fn kind(&self) -> &'static str { + match *self { + TileSurface::Color { .. } => "Color", + TileSurface::Texture { .. } => "Texture", + TileSurface::Clear => "Clear", + } + } +} + +/// Optional extra information returned by is_same when +/// logging is enabled. +#[derive(Debug, Copy, Clone, PartialEq)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub enum CompareHelperResult<T> { + /// Primitives match + Equal, + /// Counts differ + Count { + prev_count: u8, + curr_count: u8, + }, + /// Sentinel + Sentinel, + /// Two items are not equal + NotEqual { + prev: T, + curr: T, + }, + /// User callback returned true on item + PredicateTrue { + curr: T + }, +} + +/// The result of a primitive dependency comparison. Size is a u8 +/// since this is a hot path in the code, and keeping the data small +/// is a performance win. +#[derive(Debug, Copy, Clone, PartialEq)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +#[repr(u8)] +pub enum PrimitiveCompareResult { + /// Primitives match + Equal, + /// Something in the PrimitiveDescriptor was different + Descriptor, + /// The clip node content or spatial node changed + Clip, + /// The value of the transform changed + Transform, + /// An image dependency was dirty + Image, + /// The value of an opacity binding changed + OpacityBinding, + /// The value of a color binding changed + ColorBinding, +} + +/// Debugging information about why a tile was invalidated +#[derive(Debug,Clone)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub enum InvalidationReason { + /// The background color changed + BackgroundColor, + /// The opaque state of the backing native surface changed + SurfaceOpacityChanged, + /// There was no backing texture (evicted or never rendered) + NoTexture, + /// There was no backing native surface (never rendered, or recreated) + NoSurface, + /// The primitive count in the dependency list was different + PrimCount, + /// The content of one of the primitives was different + Content, + // The compositor type changed + CompositorKindChanged, + // The valid region of the tile changed + ValidRectChanged, + // The overall scale of the picture cache changed + ScaleChanged, + // The content of the sampling surface changed + SurfaceContentChanged, +} + +/// Information about a cached tile. +pub struct Tile { + /// The grid position of this tile within the picture cache + pub tile_offset: TileOffset, + /// The current world rect of this tile. + pub world_tile_rect: WorldRect, + /// The current local rect of this tile. + pub local_tile_rect: PictureRect, + /// The picture space dirty rect for this tile. + pub local_dirty_rect: PictureRect, + /// The device space dirty rect for this tile. + /// TODO(gw): We have multiple dirty rects available due to the quadtree above. In future, + /// expose these as multiple dirty rects, which will help in some cases. + pub device_dirty_rect: DeviceRect, + /// World space rect that contains valid pixels region of this tile. + pub world_valid_rect: WorldRect, + /// Device space rect that contains valid pixels region of this tile. + pub device_valid_rect: DeviceRect, + /// Uniquely describes the content of this tile, in a way that can be + /// (reasonably) efficiently hashed and compared. + pub current_descriptor: TileDescriptor, + /// The content descriptor for this tile from the previous frame. + pub prev_descriptor: TileDescriptor, + /// Handle to the backing surface for this tile. + pub surface: Option<TileSurface>, + /// If true, this tile is marked valid, and the existing texture + /// cache handle can be used. Tiles are invalidated during the + /// build_dirty_regions method. + pub is_valid: bool, + /// If true, this tile intersects with the currently visible screen + /// rect, and will be drawn. + pub is_visible: bool, + /// The tile id is stable between display lists and / or frames, + /// if the tile is retained. Useful for debugging tile evictions. + pub id: TileId, + /// If true, the tile was determined to be opaque, which means blending + /// can be disabled when drawing it. + pub is_opaque: bool, + /// Root node of the quadtree dirty rect tracker. + root: TileNode, + /// The last rendered background color on this tile. + background_color: Option<ColorF>, + /// The first reason the tile was invalidated this frame. + invalidation_reason: Option<InvalidationReason>, + /// The local space valid rect for all primitives that affect this tile. + pub local_valid_rect: PictureBox2D, + /// z-buffer id for this tile + pub z_id: ZBufferId, + pub sub_graphs: Vec<(PictureRect, Vec<(PictureCompositeMode, SurfaceIndex)>)>, +} + +impl Tile { + /// Construct a new, invalid tile. + fn new(tile_offset: TileOffset) -> Self { + let id = TileId(NEXT_TILE_ID.fetch_add(1, Ordering::Relaxed)); + + Tile { + tile_offset, + local_tile_rect: PictureRect::zero(), + world_tile_rect: WorldRect::zero(), + world_valid_rect: WorldRect::zero(), + device_valid_rect: DeviceRect::zero(), + local_dirty_rect: PictureRect::zero(), + device_dirty_rect: DeviceRect::zero(), + surface: None, + current_descriptor: TileDescriptor::new(), + prev_descriptor: TileDescriptor::new(), + is_valid: false, + is_visible: false, + id, + is_opaque: false, + root: TileNode::new_leaf(Vec::new()), + background_color: None, + invalidation_reason: None, + local_valid_rect: PictureBox2D::zero(), + z_id: ZBufferId::invalid(), + sub_graphs: Vec::new(), + } + } + + /// Print debug information about this tile to a tree printer. + fn print(&self, pt: &mut dyn PrintTreePrinter) { + pt.new_level(format!("Tile {:?}", self.id)); + pt.add_item(format!("local_tile_rect: {:?}", self.local_tile_rect)); + pt.add_item(format!("background_color: {:?}", self.background_color)); + pt.add_item(format!("invalidation_reason: {:?}", self.invalidation_reason)); + self.current_descriptor.print(pt); + pt.end_level(); + } + + /// Check if the content of the previous and current tile descriptors match + fn update_dirty_rects( + &mut self, + ctx: &TileUpdateDirtyContext, + state: &mut TileUpdateDirtyState, + invalidation_reason: &mut Option<InvalidationReason>, + frame_context: &FrameVisibilityContext, + ) -> PictureRect { + let mut prim_comparer = PrimitiveComparer::new( + &self.prev_descriptor, + &self.current_descriptor, + state.resource_cache, + state.spatial_node_comparer, + ctx.opacity_bindings, + ctx.color_bindings, + ); + + let mut dirty_rect = PictureBox2D::zero(); + self.root.update_dirty_rects( + &self.prev_descriptor.prims, + &self.current_descriptor.prims, + &mut prim_comparer, + &mut dirty_rect, + state.compare_cache, + invalidation_reason, + frame_context, + ); + + dirty_rect + } + + /// Invalidate a tile based on change in content. This + /// must be called even if the tile is not currently + /// visible on screen. We might be able to improve this + /// later by changing how ComparableVec is used. + fn update_content_validity( + &mut self, + ctx: &TileUpdateDirtyContext, + state: &mut TileUpdateDirtyState, + frame_context: &FrameVisibilityContext, + ) { + // Check if the contents of the primitives, clips, and + // other dependencies are the same. + state.compare_cache.clear(); + let mut invalidation_reason = None; + let dirty_rect = self.update_dirty_rects( + ctx, + state, + &mut invalidation_reason, + frame_context, + ); + if !dirty_rect.is_empty() { + self.invalidate( + Some(dirty_rect), + invalidation_reason.expect("bug: no invalidation_reason"), + ); + } + if ctx.invalidate_all { + self.invalidate(None, InvalidationReason::ScaleChanged); + } + // TODO(gw): We can avoid invalidating the whole tile in some cases here, + // but it should be a fairly rare invalidation case. + if self.current_descriptor.local_valid_rect != self.prev_descriptor.local_valid_rect { + self.invalidate(None, InvalidationReason::ValidRectChanged); + state.composite_state.dirty_rects_are_valid = false; + } + } + + /// Invalidate this tile. If `invalidation_rect` is None, the entire + /// tile is invalidated. + fn invalidate( + &mut self, + invalidation_rect: Option<PictureRect>, + reason: InvalidationReason, + ) { + self.is_valid = false; + + match invalidation_rect { + Some(rect) => { + self.local_dirty_rect = self.local_dirty_rect.union(&rect); + } + None => { + self.local_dirty_rect = self.local_tile_rect; + } + } + + if self.invalidation_reason.is_none() { + self.invalidation_reason = Some(reason); + } + } + + /// Called during pre_update of a tile cache instance. Allows the + /// tile to setup state before primitive dependency calculations. + fn pre_update( + &mut self, + ctx: &TilePreUpdateContext, + ) { + self.local_tile_rect = PictureRect::from_origin_and_size( + PicturePoint::new( + self.tile_offset.x as f32 * ctx.tile_size.width, + self.tile_offset.y as f32 * ctx.tile_size.height, + ), + ctx.tile_size, + ); + // TODO(gw): This is a hack / fix for Box2D::union in euclid not working with + // zero sized rect accumulation. Once that lands, we'll revert this + // to be zero. + self.local_valid_rect = PictureBox2D::new( + PicturePoint::new( 1.0e32, 1.0e32), + PicturePoint::new(-1.0e32, -1.0e32), + ); + self.invalidation_reason = None; + self.sub_graphs.clear(); + + self.world_tile_rect = ctx.pic_to_world_mapper + .map(&self.local_tile_rect) + .expect("bug: map local tile rect"); + + // Check if this tile is currently on screen. + self.is_visible = self.world_tile_rect.intersects(&ctx.global_screen_world_rect); + + // If the tile isn't visible, early exit, skipping the normal set up to + // validate dependencies. Instead, we will only compare the current tile + // dependencies the next time it comes into view. + if !self.is_visible { + return; + } + + if ctx.background_color != self.background_color { + self.invalidate(None, InvalidationReason::BackgroundColor); + self.background_color = ctx.background_color; + } + + // Clear any dependencies so that when we rebuild them we + // can compare if the tile has the same content. + mem::swap( + &mut self.current_descriptor, + &mut self.prev_descriptor, + ); + self.current_descriptor.clear(); + self.root.clear(self.local_tile_rect); + + // Since this tile is determined to be visible, it will get updated + // dependencies, so update the frame id we are storing dependencies for. + self.current_descriptor.last_updated_frame_id = ctx.frame_id; + } + + /// Add dependencies for a given primitive to this tile. + fn add_prim_dependency( + &mut self, + info: &PrimitiveDependencyInfo, + ) { + // If this tile isn't currently visible, we don't want to update the dependencies + // for this tile, as an optimization, since it won't be drawn anyway. + if !self.is_visible { + return; + } + + // Incorporate the bounding rect of the primitive in the local valid rect + // for this tile. This is used to minimize the size of the scissor rect + // during rasterization and the draw rect during composition of partial tiles. + self.local_valid_rect = self.local_valid_rect.union(&info.prim_clip_box); + + // TODO(gw): The prim_clip_rect can be impacted by the clip rect of the display port, + // which can cause invalidations when a new display list with changed + // display port is received. To work around this, clamp the prim clip rect + // to the tile boundaries - if the clip hasn't affected the tile, then the + // changed clip can't affect the content of the primitive on this tile. + // In future, we could consider supplying the display port clip from Gecko + // in a different way (e.g. as a scroll frame clip) which still provides + // the desired clip for checkerboarding, but doesn't require this extra + // work below. + + // TODO(gw): This is a hot part of the code - we could probably optimize further by: + // - Using min/max instead of clamps below (if we guarantee the rects are well formed) + + let tile_p0 = self.local_tile_rect.min; + let tile_p1 = self.local_tile_rect.max; + + let prim_clip_box = PictureBox2D::new( + PicturePoint::new( + clampf(info.prim_clip_box.min.x, tile_p0.x, tile_p1.x), + clampf(info.prim_clip_box.min.y, tile_p0.y, tile_p1.y), + ), + PicturePoint::new( + clampf(info.prim_clip_box.max.x, tile_p0.x, tile_p1.x), + clampf(info.prim_clip_box.max.y, tile_p0.y, tile_p1.y), + ), + ); + + // Update the tile descriptor, used for tile comparison during scene swaps. + let prim_index = PrimitiveDependencyIndex(self.current_descriptor.prims.len() as u32); + + // Encode the deps for this primitive in the `dep_data` byte buffer + let dep_offset = self.current_descriptor.dep_data.len() as u32; + let mut dep_count = 0; + + for clip in &info.clips { + dep_count += 1; + poke_into_vec( + &PrimitiveDependency::Clip { + clip: *clip, + }, + &mut self.current_descriptor.dep_data, + ); + } + + for spatial_node_index in &info.spatial_nodes { + dep_count += 1; + poke_into_vec( + &PrimitiveDependency::SpatialNode { + index: *spatial_node_index, + }, + &mut self.current_descriptor.dep_data, + ); + } + + for image in &info.images { + dep_count += 1; + poke_into_vec( + &PrimitiveDependency::Image { + image: *image, + }, + &mut self.current_descriptor.dep_data, + ); + } + + for binding in &info.opacity_bindings { + dep_count += 1; + poke_into_vec( + &PrimitiveDependency::OpacityBinding { + binding: *binding, + }, + &mut self.current_descriptor.dep_data, + ); + } + + if let Some(ref binding) = info.color_binding { + dep_count += 1; + poke_into_vec( + &PrimitiveDependency::ColorBinding { + binding: *binding, + }, + &mut self.current_descriptor.dep_data, + ); + } + + self.current_descriptor.prims.push(PrimitiveDescriptor { + prim_uid: info.prim_uid, + prim_clip_box, + dep_offset, + dep_count, + }); + + // Add this primitive to the dirty rect quadtree. + self.root.add_prim(prim_index, &info.prim_clip_box); + } + + /// Called during tile cache instance post_update. Allows invalidation and dirty + /// rect calculation after primitive dependencies have been updated. + fn update_dirty_and_valid_rects( + &mut self, + ctx: &TileUpdateDirtyContext, + state: &mut TileUpdateDirtyState, + frame_context: &FrameVisibilityContext, + ) { + // Ensure peek-poke constraint is met, that `dep_data` is large enough + ensure_red_zone::<PrimitiveDependency>(&mut self.current_descriptor.dep_data); + + // Register the frame id of this tile with the spatial node comparer, to ensure + // that it doesn't GC any spatial nodes from the comparer that are referenced + // by this tile. Must be done before we early exit below, so that we retain + // spatial node info even for tiles that are currently not visible. + state.spatial_node_comparer.retain_for_frame(self.current_descriptor.last_updated_frame_id); + + // If tile is not visible, just early out from here - we don't update dependencies + // so don't want to invalidate, merge, split etc. The tile won't need to be drawn + // (and thus updated / invalidated) until it is on screen again. + if !self.is_visible { + return; + } + + // Calculate the overall valid rect for this tile. + self.current_descriptor.local_valid_rect = self.local_valid_rect; + + // TODO(gw): In theory, the local tile rect should always have an + // intersection with the overall picture rect. In practice, + // due to some accuracy issues with how fract_offset (and + // fp accuracy) are used in the calling method, this isn't + // always true. In this case, it's safe to set the local + // valid rect to zero, which means it will be clipped out + // and not affect the scene. In future, we should fix the + // accuracy issue above, so that this assumption holds, but + // it shouldn't have any noticeable effect on performance + // or memory usage (textures should never get allocated). + self.current_descriptor.local_valid_rect = self.local_tile_rect + .intersection(&ctx.local_rect) + .and_then(|r| r.intersection(&self.current_descriptor.local_valid_rect)) + .unwrap_or_else(PictureRect::zero); + + // The device_valid_rect is referenced during `update_content_validity` so it + // must be updated here first. + self.world_valid_rect = ctx.pic_to_world_mapper + .map(&self.current_descriptor.local_valid_rect) + .expect("bug: map local valid rect"); + + // The device rect is guaranteed to be aligned on a device pixel - the round + // is just to deal with float accuracy. However, the valid rect is not + // always aligned to a device pixel. To handle this, round out to get all + // required pixels, and intersect with the tile device rect. + let device_rect = (self.world_tile_rect * ctx.global_device_pixel_scale).round(); + self.device_valid_rect = (self.world_valid_rect * ctx.global_device_pixel_scale) + .round_out() + .intersection(&device_rect) + .unwrap_or_else(DeviceRect::zero); + + // Invalidate the tile based on the content changing. + self.update_content_validity(ctx, state, frame_context); + } + + /// Called during tile cache instance post_update. Allows invalidation and dirty + /// rect calculation after primitive dependencies have been updated. + fn post_update( + &mut self, + ctx: &TilePostUpdateContext, + state: &mut TilePostUpdateState, + frame_context: &FrameVisibilityContext, + ) { + // If tile is not visible, just early out from here - we don't update dependencies + // so don't want to invalidate, merge, split etc. The tile won't need to be drawn + // (and thus updated / invalidated) until it is on screen again. + if !self.is_visible { + return; + } + + // If there are no primitives there is no need to draw or cache it. + // Bug 1719232 - The final device valid rect does not always describe a non-empty + // region. Cull the tile as a workaround. + if self.current_descriptor.prims.is_empty() || self.device_valid_rect.is_empty() { + // If there is a native compositor surface allocated for this (now empty) tile + // it must be freed here, otherwise the stale tile with previous contents will + // be composited. If the tile subsequently gets new primitives added to it, the + // surface will be re-allocated when it's added to the composite draw list. + if let Some(TileSurface::Texture { descriptor: SurfaceTextureDescriptor::Native { mut id, .. }, .. }) = self.surface.take() { + if let Some(id) = id.take() { + state.resource_cache.destroy_compositor_tile(id); + } + } + + self.is_visible = false; + return; + } + + // Check if this tile can be considered opaque. Opacity state must be updated only + // after all early out checks have been performed. Otherwise, we might miss updating + // the native surface next time this tile becomes visible. + let clipped_rect = self.current_descriptor.local_valid_rect + .intersection(&ctx.local_clip_rect) + .unwrap_or_else(PictureRect::zero); + + let has_opaque_bg_color = self.background_color.map_or(false, |c| c.a >= 1.0); + let has_opaque_backdrop = ctx.backdrop.map_or(false, |b| b.opaque_rect.contains_box(&clipped_rect)); + let is_opaque = has_opaque_bg_color || has_opaque_backdrop; + + // Set the correct z_id for this tile + self.z_id = ctx.z_id; + + if is_opaque != self.is_opaque { + // If opacity changed, the native compositor surface and all tiles get invalidated. + // (this does nothing if not using native compositor mode). + // TODO(gw): This property probably changes very rarely, so it is OK to invalidate + // everything in this case. If it turns out that this isn't true, we could + // consider other options, such as per-tile opacity (natively supported + // on CoreAnimation, and supported if backed by non-virtual surfaces in + // DirectComposition). + if let Some(TileSurface::Texture { descriptor: SurfaceTextureDescriptor::Native { ref mut id, .. }, .. }) = self.surface { + if let Some(id) = id.take() { + state.resource_cache.destroy_compositor_tile(id); + } + } + + // Invalidate the entire tile to force a redraw. + self.invalidate(None, InvalidationReason::SurfaceOpacityChanged); + self.is_opaque = is_opaque; + } + + // Check if the selected composite mode supports dirty rect updates. For Draw composite + // mode, we can always update the content with smaller dirty rects, unless there is a + // driver bug to workaround. For native composite mode, we can only use dirty rects if + // the compositor supports partial surface updates. + let (supports_dirty_rects, supports_simple_prims) = match state.composite_state.compositor_kind { + CompositorKind::Draw { .. } => { + (frame_context.config.gpu_supports_render_target_partial_update, true) + } + CompositorKind::Native { capabilities, .. } => { + (capabilities.max_update_rects > 0, false) + } + }; + + // TODO(gw): Consider using smaller tiles and/or tile splits for + // native compositors that don't support dirty rects. + if supports_dirty_rects { + // Only allow splitting for normal content sized tiles + if ctx.current_tile_size == state.resource_cache.picture_textures.default_tile_size() { + let max_split_level = 3; + + // Consider splitting / merging dirty regions + self.root.maybe_merge_or_split( + 0, + &self.current_descriptor.prims, + max_split_level, + ); + } + } + + // The dirty rect will be set correctly by now. If the underlying platform + // doesn't support partial updates, and this tile isn't valid, force the dirty + // rect to be the size of the entire tile. + if !self.is_valid && !supports_dirty_rects { + self.local_dirty_rect = self.local_tile_rect; + } + + // See if this tile is a simple color, in which case we can just draw + // it as a rect, and avoid allocating a texture surface and drawing it. + // TODO(gw): Initial native compositor interface doesn't support simple + // color tiles. We can definitely support this in DC, so this + // should be added as a follow up. + let is_simple_prim = + ctx.backdrop.map_or(false, |b| b.kind.is_some()) && + self.current_descriptor.prims.len() == 1 && + self.is_opaque && + supports_simple_prims; + + // Set up the backing surface for this tile. + let surface = if is_simple_prim { + // If we determine the tile can be represented by a color, set the + // surface unconditionally (this will drop any previously used + // texture cache backing surface). + match ctx.backdrop.unwrap().kind { + Some(BackdropKind::Color { color }) => { + TileSurface::Color { + color, + } + } + Some(BackdropKind::Clear) => { + TileSurface::Clear + } + None => { + // This should be prevented by the is_simple_prim check above. + unreachable!(); + } + } + } else { + // If this tile will be backed by a surface, we want to retain + // the texture handle from the previous frame, if possible. If + // the tile was previously a color, or not set, then just set + // up a new texture cache handle. + match self.surface.take() { + Some(TileSurface::Texture { descriptor }) => { + // Reuse the existing descriptor and vis mask + TileSurface::Texture { + descriptor, + } + } + Some(TileSurface::Color { .. }) | Some(TileSurface::Clear) | None => { + // This is the case where we are constructing a tile surface that + // involves drawing to a texture. Create the correct surface + // descriptor depending on the compositing mode that will read + // the output. + let descriptor = match state.composite_state.compositor_kind { + CompositorKind::Draw { .. } => { + // For a texture cache entry, create an invalid handle that + // will be allocated when update_picture_cache is called. + SurfaceTextureDescriptor::TextureCache { + handle: None, + } + } + CompositorKind::Native { .. } => { + // Create a native surface surface descriptor, but don't allocate + // a surface yet. The surface is allocated *after* occlusion + // culling occurs, so that only visible tiles allocate GPU memory. + SurfaceTextureDescriptor::Native { + id: None, + } + } + }; + + TileSurface::Texture { + descriptor, + } + } + } + }; + + // Store the current surface backing info for use during batching. + self.surface = Some(surface); + } +} + +/// Defines a key that uniquely identifies a primitive instance. +#[derive(Debug, Clone)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub struct PrimitiveDescriptor { + pub prim_uid: ItemUid, + pub prim_clip_box: PictureBox2D, + // TODO(gw): These two fields could be packed as a u24/u8 + pub dep_offset: u32, + pub dep_count: u32, +} + +impl PartialEq for PrimitiveDescriptor { + fn eq(&self, other: &Self) -> bool { + const EPSILON: f32 = 0.001; + + if self.prim_uid != other.prim_uid { + return false; + } + + if !self.prim_clip_box.min.x.approx_eq_eps(&other.prim_clip_box.min.x, &EPSILON) { + return false; + } + if !self.prim_clip_box.min.y.approx_eq_eps(&other.prim_clip_box.min.y, &EPSILON) { + return false; + } + if !self.prim_clip_box.max.x.approx_eq_eps(&other.prim_clip_box.max.x, &EPSILON) { + return false; + } + if !self.prim_clip_box.max.y.approx_eq_eps(&other.prim_clip_box.max.y, &EPSILON) { + return false; + } + + if self.dep_count != other.dep_count { + return false; + } + + true + } +} + +/// Uniquely describes the content of this tile, in a way that can be +/// (reasonably) efficiently hashed and compared. +#[cfg_attr(any(feature="capture",feature="replay"), derive(Clone))] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub struct TileDescriptor { + /// List of primitive instance unique identifiers. The uid is guaranteed + /// to uniquely describe the content of the primitive template, while + /// the other parameters describe the clip chain and instance params. + prims: Vec<PrimitiveDescriptor>, + + /// Picture space rect that contains valid pixels region of this tile. + pub local_valid_rect: PictureRect, + + /// The last frame this tile had its dependencies updated (dependency updating is + /// skipped if a tile is off-screen). + last_updated_frame_id: FrameId, + + /// Packed per-prim dependency information + dep_data: Vec<u8>, +} + +impl TileDescriptor { + fn new() -> Self { + TileDescriptor { + local_valid_rect: PictureRect::zero(), + dep_data: Vec::new(), + prims: Vec::new(), + last_updated_frame_id: FrameId::INVALID, + } + } + + /// Print debug information about this tile descriptor to a tree printer. + fn print(&self, pt: &mut dyn PrintTreePrinter) { + pt.new_level("current_descriptor".to_string()); + + pt.new_level("prims".to_string()); + for prim in &self.prims { + pt.new_level(format!("prim uid={}", prim.prim_uid.get_uid())); + pt.add_item(format!("clip: p0={},{} p1={},{}", + prim.prim_clip_box.min.x, + prim.prim_clip_box.min.y, + prim.prim_clip_box.max.x, + prim.prim_clip_box.max.y, + )); + pt.end_level(); + } + pt.end_level(); + + pt.end_level(); + } + + /// Clear the dependency information for a tile, when the dependencies + /// are being rebuilt. + fn clear(&mut self) { + self.local_valid_rect = PictureRect::zero(); + self.prims.clear(); + self.dep_data.clear(); + } +} + +/// Represents the dirty region of a tile cache picture. +#[derive(Clone)] +pub struct DirtyRegion { + /// The overall dirty rect, a combination of dirty_rects + pub combined: WorldRect, + + /// Spatial node of the picture cache this region represents + spatial_node_index: SpatialNodeIndex, +} + +impl DirtyRegion { + /// Construct a new dirty region tracker. + pub fn new( + spatial_node_index: SpatialNodeIndex, + ) -> Self { + DirtyRegion { + combined: WorldRect::zero(), + spatial_node_index, + } + } + + /// Reset the dirty regions back to empty + pub fn reset( + &mut self, + spatial_node_index: SpatialNodeIndex, + ) { + self.combined = WorldRect::zero(); + self.spatial_node_index = spatial_node_index; + } + + /// Add a dirty region to the tracker. Returns the visibility mask that corresponds to + /// this region in the tracker. + pub fn add_dirty_region( + &mut self, + rect_in_pic_space: PictureRect, + spatial_tree: &SpatialTree, + ) { + let map_pic_to_world = SpaceMapper::new_with_target( + spatial_tree.root_reference_frame_index(), + self.spatial_node_index, + WorldRect::max_rect(), + spatial_tree, + ); + + let world_rect = map_pic_to_world + .map(&rect_in_pic_space) + .expect("bug"); + + // Include this in the overall dirty rect + self.combined = self.combined.union(&world_rect); + } +} + +// TODO(gw): Tidy this up by: +// - Rename Clear variant to something more appropriate to what it does +// - Add an Other variant for things like opaque gradient backdrops +#[derive(Debug, Copy, Clone)] +pub enum BackdropKind { + Color { + color: ColorF, + }, + Clear, +} + +/// Stores information about the calculated opaque backdrop of this slice. +#[derive(Debug, Copy, Clone)] +pub struct BackdropInfo { + /// The picture space rectangle that is known to be opaque. This is used + /// to determine where subpixel AA can be used, and where alpha blending + /// can be disabled. + pub opaque_rect: PictureRect, + /// If the backdrop covers the entire slice with an opaque color, this + /// will be set and can be used as a clear color for the slice's tiles. + pub spanning_opaque_color: Option<ColorF>, + /// Kind of the backdrop + pub kind: Option<BackdropKind>, + /// The picture space rectangle of the backdrop, if kind is set. + pub backdrop_rect: PictureRect, +} + +impl BackdropInfo { + fn empty() -> Self { + BackdropInfo { + opaque_rect: PictureRect::zero(), + spanning_opaque_color: None, + kind: None, + backdrop_rect: PictureRect::zero(), + } + } +} + +/// Represents the native surfaces created for a picture cache, if using +/// a native compositor. An opaque and alpha surface is always created, +/// but tiles are added to a surface based on current opacity. If the +/// calculated opacity of a tile changes, the tile is invalidated and +/// attached to a different native surface. This means that we don't +/// need to invalidate the entire surface if only some tiles are changing +/// opacity. It also means we can take advantage of opaque tiles on cache +/// slices where only some of the tiles are opaque. There is an assumption +/// that creating a native surface is cheap, and only when a tile is added +/// to a surface is there a significant cost. This assumption holds true +/// for the current native compositor implementations on Windows and Mac. +pub struct NativeSurface { + /// Native surface for opaque tiles + pub opaque: NativeSurfaceId, + /// Native surface for alpha tiles + pub alpha: NativeSurfaceId, +} + +/// Hash key for an external native compositor surface +#[derive(PartialEq, Eq, Hash)] +pub struct ExternalNativeSurfaceKey { + /// The YUV/RGB image keys that are used to draw this surface. + pub image_keys: [ImageKey; 3], + /// If this is not an 'external' compositor surface created via + /// Compositor::create_external_surface, this is set to the + /// current device size of the surface. + pub size: Option<DeviceIntSize>, +} + +/// Information about a native compositor surface cached between frames. +pub struct ExternalNativeSurface { + /// If true, the surface was used this frame. Used for a simple form + /// of GC to remove old surfaces. + pub used_this_frame: bool, + /// The native compositor surface handle + pub native_surface_id: NativeSurfaceId, + /// List of image keys, and current image generations, that are drawn in this surface. + /// The image generations are used to check if the compositor surface is dirty and + /// needs to be updated. + pub image_dependencies: [ImageDependency; 3], +} + +/// The key that identifies a tile cache instance. For now, it's simple the index of +/// the slice as it was created during scene building. +#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub struct SliceId(usize); + +impl SliceId { + pub fn new(index: usize) -> Self { + SliceId(index) + } +} + +/// Information that is required to reuse or create a new tile cache. Created +/// during scene building and passed to the render backend / frame builder. +pub struct TileCacheParams { + // Index of the slice (also effectively the key of the tile cache, though we use SliceId where that matters) + pub slice: usize, + // Flags describing content of this cache (e.g. scrollbars) + pub slice_flags: SliceFlags, + // The anchoring spatial node / scroll root + pub spatial_node_index: SpatialNodeIndex, + // Optional background color of this tilecache. If present, can be used as an optimization + // to enable opaque blending and/or subpixel AA in more places. + pub background_color: Option<ColorF>, + // Node in the clip-tree that defines where we exclude clips from child prims + pub shared_clip_node_id: ClipNodeId, + // Clip leaf that is used to build the clip-chain for this tile cache. + pub shared_clip_leaf_id: Option<ClipLeafId>, + // Virtual surface sizes are always square, so this represents both the width and height + pub virtual_surface_size: i32, + // The number of compositor surfaces that are being requested for this tile cache. + // This is only a suggestion - the tile cache will clamp this as a reasonable number + // and only promote a limited number of surfaces. + pub compositor_surface_count: usize, +} + +/// Defines which sub-slice (effectively a z-index) a primitive exists on within +/// a picture cache instance. +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)] +pub struct SubSliceIndex(u8); + +impl SubSliceIndex { + pub const DEFAULT: SubSliceIndex = SubSliceIndex(0); + + pub fn new(index: usize) -> Self { + SubSliceIndex(index as u8) + } + + /// Return true if this sub-slice is the primary sub-slice (for now, we assume + /// that only the primary sub-slice may be opaque and support subpixel AA, for example). + pub fn is_primary(&self) -> bool { + self.0 == 0 + } + + /// Get an array index for this sub-slice + pub fn as_usize(&self) -> usize { + self.0 as usize + } +} + +/// Wrapper struct around an external surface descriptor with a little more information +/// that the picture caching code needs. +pub struct CompositorSurface { + // External surface descriptor used by compositing logic + pub descriptor: ExternalSurfaceDescriptor, + // The compositor surface rect + any intersecting prims. Later prims that intersect + // with this must be added to the next sub-slice. + prohibited_rect: PictureRect, + // If the compositor surface content is opaque. + pub is_opaque: bool, +} + +/// A SubSlice represents a potentially overlapping set of tiles within a picture cache. Most +/// picture cache instances will have only a single sub-slice. The exception to this is when +/// a picture cache has compositor surfaces, in which case sub slices are used to interleave +/// content under or order the compositor surface(s). +pub struct SubSlice { + /// Hash of tiles present in this picture. + pub tiles: FastHashMap<TileOffset, Box<Tile>>, + /// The allocated compositor surfaces for this picture cache. May be None if + /// not using native compositor, or if the surface was destroyed and needs + /// to be reallocated next time this surface contains valid tiles. + pub native_surface: Option<NativeSurface>, + /// List of compositor surfaces that have been promoted from primitives + /// in this tile cache. + pub compositor_surfaces: Vec<CompositorSurface>, + /// List of visible tiles to be composited for this subslice + pub composite_tiles: Vec<CompositeTile>, + /// Compositor descriptors of visible, opaque tiles (used by composite_state.push_surface) + pub opaque_tile_descriptors: Vec<CompositeTileDescriptor>, + /// Compositor descriptors of visible, alpha tiles (used by composite_state.push_surface) + pub alpha_tile_descriptors: Vec<CompositeTileDescriptor>, +} + +impl SubSlice { + /// Construct a new sub-slice + fn new() -> Self { + SubSlice { + tiles: FastHashMap::default(), + native_surface: None, + compositor_surfaces: Vec::new(), + composite_tiles: Vec::new(), + opaque_tile_descriptors: Vec::new(), + alpha_tile_descriptors: Vec::new(), + } + } + + /// Reset the list of compositor surfaces that follow this sub-slice. + /// Built per-frame, since APZ may change whether an image is suitable to be a compositor surface. + fn reset(&mut self) { + self.compositor_surfaces.clear(); + self.composite_tiles.clear(); + self.opaque_tile_descriptors.clear(); + self.alpha_tile_descriptors.clear(); + } + + /// Resize the tile grid to match a new tile bounds + fn resize(&mut self, new_tile_rect: TileRect) -> FastHashMap<TileOffset, Box<Tile>> { + let mut old_tiles = mem::replace(&mut self.tiles, FastHashMap::default()); + self.tiles.reserve(new_tile_rect.area() as usize); + + for y in new_tile_rect.min.y .. new_tile_rect.max.y { + for x in new_tile_rect.min.x .. new_tile_rect.max.x { + let key = TileOffset::new(x, y); + let tile = old_tiles + .remove(&key) + .unwrap_or_else(|| { + Box::new(Tile::new(key)) + }); + self.tiles.insert(key, tile); + } + } + + old_tiles + } +} + +pub struct BackdropSurface { + pub id: NativeSurfaceId, + color: ColorF, + pub device_rect: DeviceRect, +} + +/// Represents a cache of tiles that make up a picture primitives. +pub struct TileCacheInstance { + /// Index of the tile cache / slice for this frame builder. It's determined + /// by the setup_picture_caching method during flattening, which splits the + /// picture tree into multiple slices. It's used as a simple input to the tile + /// keys. It does mean we invalidate tiles if a new layer gets inserted / removed + /// between display lists - this seems very unlikely to occur on most pages, but + /// can be revisited if we ever notice that. + pub slice: usize, + /// Propagated information about the slice + pub slice_flags: SliceFlags, + /// The currently selected tile size to use for this cache + pub current_tile_size: DeviceIntSize, + /// The list of sub-slices in this tile cache + pub sub_slices: Vec<SubSlice>, + /// The positioning node for this tile cache. + pub spatial_node_index: SpatialNodeIndex, + /// List of opacity bindings, with some extra information + /// about whether they changed since last frame. + opacity_bindings: FastHashMap<PropertyBindingId, OpacityBindingInfo>, + /// Switch back and forth between old and new bindings hashmaps to avoid re-allocating. + old_opacity_bindings: FastHashMap<PropertyBindingId, OpacityBindingInfo>, + /// A helper to compare transforms between previous and current frame. + spatial_node_comparer: SpatialNodeComparer, + /// List of color bindings, with some extra information + /// about whether they changed since last frame. + color_bindings: FastHashMap<PropertyBindingId, ColorBindingInfo>, + /// Switch back and forth between old and new bindings hashmaps to avoid re-allocating. + old_color_bindings: FastHashMap<PropertyBindingId, ColorBindingInfo>, + /// The current dirty region tracker for this picture. + pub dirty_region: DirtyRegion, + /// Current size of tiles in picture units. + tile_size: PictureSize, + /// Tile coords of the currently allocated grid. + tile_rect: TileRect, + /// Pre-calculated versions of the tile_rect above, used to speed up the + /// calculations in get_tile_coords_for_rect. + tile_bounds_p0: TileOffset, + tile_bounds_p1: TileOffset, + /// Local rect (unclipped) of the picture this cache covers. + pub local_rect: PictureRect, + /// The local clip rect, from the shared clips of this picture. + pub local_clip_rect: PictureRect, + /// The screen rect, transformed to local picture space. + pub screen_rect_in_pic_space: PictureRect, + /// The surface index that this tile cache will be drawn into. + surface_index: SurfaceIndex, + /// The background color from the renderer. If this is set opaque, we know it's + /// fine to clear the tiles to this and allow subpixel text on the first slice. + pub background_color: Option<ColorF>, + /// Information about the calculated backdrop content of this cache. + pub backdrop: BackdropInfo, + /// The allowed subpixel mode for this surface, which depends on the detected + /// opacity of the background. + pub subpixel_mode: SubpixelMode, + // Node in the clip-tree that defines where we exclude clips from child prims + pub shared_clip_node_id: ClipNodeId, + // Clip leaf that is used to build the clip-chain for this tile cache. + pub shared_clip_leaf_id: Option<ClipLeafId>, + /// The number of frames until this cache next evaluates what tile size to use. + /// If a picture rect size is regularly changing just around a size threshold, + /// we don't want to constantly invalidate and reallocate different tile size + /// configuration each frame. + frames_until_size_eval: usize, + /// For DirectComposition, virtual surfaces don't support negative coordinates. However, + /// picture cache tile coordinates can be negative. To handle this, we apply an offset + /// to each tile in DirectComposition. We want to change this as little as possible, + /// to avoid invalidating tiles. However, if we have a picture cache tile coordinate + /// which is outside the virtual surface bounds, we must change this to allow + /// correct remapping of the coordinates passed to BeginDraw in DC. + virtual_offset: DeviceIntPoint, + /// keep around the hash map used as compare_cache to avoid reallocating it each + /// frame. + compare_cache: FastHashMap<PrimitiveComparisonKey, PrimitiveCompareResult>, + /// The currently considered tile size override. Used to check if we should + /// re-evaluate tile size, even if the frame timer hasn't expired. + tile_size_override: Option<DeviceIntSize>, + /// A cache of compositor surfaces that are retained between frames + pub external_native_surface_cache: FastHashMap<ExternalNativeSurfaceKey, ExternalNativeSurface>, + /// Current frame ID of this tile cache instance. Used for book-keeping / garbage collecting + frame_id: FrameId, + /// Registered transform in CompositeState for this picture cache + pub transform_index: CompositorTransformIndex, + /// Current transform mapping local picture space to compositor surface space + local_to_surface: ScaleOffset, + /// If true, we need to invalidate all tiles during `post_update` + invalidate_all_tiles: bool, + /// Current transform mapping compositor surface space to final device space + surface_to_device: ScaleOffset, + /// The current raster scale for tiles in this cache + current_raster_scale: f32, + /// Depth of off-screen surfaces that are currently pushed during dependency updates + current_surface_traversal_depth: usize, + /// A list of extra dirty invalidation tests that can only be checked once we + /// know the dirty rect of all tiles + deferred_dirty_tests: Vec<DeferredDirtyTest>, + /// Is there a backdrop associated with this cache + found_prims_after_backdrop: bool, + pub backdrop_surface: Option<BackdropSurface>, +} + +enum SurfacePromotionResult { + Failed, + Success, +} + +impl TileCacheInstance { + pub fn new(params: TileCacheParams) -> Self { + // Determine how many sub-slices we need. Clamp to an arbitrary limit to ensure + // we don't create a huge number of OS compositor tiles and sub-slices. + let sub_slice_count = params.compositor_surface_count.min(MAX_COMPOSITOR_SURFACES) + 1; + + let mut sub_slices = Vec::with_capacity(sub_slice_count); + for _ in 0 .. sub_slice_count { + sub_slices.push(SubSlice::new()); + } + + TileCacheInstance { + slice: params.slice, + slice_flags: params.slice_flags, + spatial_node_index: params.spatial_node_index, + sub_slices, + opacity_bindings: FastHashMap::default(), + old_opacity_bindings: FastHashMap::default(), + spatial_node_comparer: SpatialNodeComparer::new(), + color_bindings: FastHashMap::default(), + old_color_bindings: FastHashMap::default(), + dirty_region: DirtyRegion::new(params.spatial_node_index), + tile_size: PictureSize::zero(), + tile_rect: TileRect::zero(), + tile_bounds_p0: TileOffset::zero(), + tile_bounds_p1: TileOffset::zero(), + local_rect: PictureRect::zero(), + local_clip_rect: PictureRect::zero(), + screen_rect_in_pic_space: PictureRect::zero(), + surface_index: SurfaceIndex(0), + background_color: params.background_color, + backdrop: BackdropInfo::empty(), + subpixel_mode: SubpixelMode::Allow, + shared_clip_node_id: params.shared_clip_node_id, + shared_clip_leaf_id: params.shared_clip_leaf_id, + current_tile_size: DeviceIntSize::zero(), + frames_until_size_eval: 0, + // Default to centering the virtual offset in the middle of the DC virtual surface + virtual_offset: DeviceIntPoint::new( + params.virtual_surface_size / 2, + params.virtual_surface_size / 2, + ), + compare_cache: FastHashMap::default(), + tile_size_override: None, + external_native_surface_cache: FastHashMap::default(), + frame_id: FrameId::INVALID, + transform_index: CompositorTransformIndex::INVALID, + surface_to_device: ScaleOffset::identity(), + local_to_surface: ScaleOffset::identity(), + invalidate_all_tiles: true, + current_raster_scale: 1.0, + current_surface_traversal_depth: 0, + deferred_dirty_tests: Vec::new(), + found_prims_after_backdrop: false, + backdrop_surface: None, + } + } + + /// Return the total number of tiles allocated by this tile cache + pub fn tile_count(&self) -> usize { + self.tile_rect.area() as usize * self.sub_slices.len() + } + + /// Trims memory held by the tile cache, such as native surfaces. + pub fn memory_pressure(&mut self, resource_cache: &mut ResourceCache) { + for sub_slice in &mut self.sub_slices { + for tile in sub_slice.tiles.values_mut() { + if let Some(TileSurface::Texture { descriptor: SurfaceTextureDescriptor::Native { ref mut id, .. }, .. }) = tile.surface { + // Reseting the id to None with take() ensures that a new + // tile will be allocated during the next frame build. + if let Some(id) = id.take() { + resource_cache.destroy_compositor_tile(id); + } + } + } + if let Some(native_surface) = sub_slice.native_surface.take() { + resource_cache.destroy_compositor_surface(native_surface.opaque); + resource_cache.destroy_compositor_surface(native_surface.alpha); + } + } + } + + /// Reset this tile cache with the updated parameters from a new scene + /// that has arrived. This allows the tile cache to be retained across + /// new scenes. + pub fn prepare_for_new_scene( + &mut self, + params: TileCacheParams, + resource_cache: &mut ResourceCache, + ) { + // We should only receive updated state for matching slice key + assert_eq!(self.slice, params.slice); + + // Determine how many sub-slices we need, based on how many compositor surface prims are + // in the supplied primitive list. + let required_sub_slice_count = params.compositor_surface_count.min(MAX_COMPOSITOR_SURFACES) + 1; + + if self.sub_slices.len() != required_sub_slice_count { + self.tile_rect = TileRect::zero(); + + if self.sub_slices.len() > required_sub_slice_count { + let old_sub_slices = self.sub_slices.split_off(required_sub_slice_count); + + for mut sub_slice in old_sub_slices { + for tile in sub_slice.tiles.values_mut() { + if let Some(TileSurface::Texture { descriptor: SurfaceTextureDescriptor::Native { ref mut id, .. }, .. }) = tile.surface { + if let Some(id) = id.take() { + resource_cache.destroy_compositor_tile(id); + } + } + } + + if let Some(native_surface) = sub_slice.native_surface { + resource_cache.destroy_compositor_surface(native_surface.opaque); + resource_cache.destroy_compositor_surface(native_surface.alpha); + } + } + } else { + while self.sub_slices.len() < required_sub_slice_count { + self.sub_slices.push(SubSlice::new()); + } + } + } + + // Store the parameters from the scene builder for this slice. Other + // params in the tile cache are retained and reused, or are always + // updated during pre/post_update. + self.slice_flags = params.slice_flags; + self.spatial_node_index = params.spatial_node_index; + self.background_color = params.background_color; + self.shared_clip_leaf_id = params.shared_clip_leaf_id; + self.shared_clip_node_id = params.shared_clip_node_id; + + // Since the slice flags may have changed, ensure we re-evaluate the + // appropriate tile size for this cache next update. + self.frames_until_size_eval = 0; + } + + /// Destroy any manually managed resources before this picture cache is + /// destroyed, such as native compositor surfaces. + pub fn destroy( + self, + resource_cache: &mut ResourceCache, + ) { + for sub_slice in self.sub_slices { + if let Some(native_surface) = sub_slice.native_surface { + resource_cache.destroy_compositor_surface(native_surface.opaque); + resource_cache.destroy_compositor_surface(native_surface.alpha); + } + } + + for (_, external_surface) in self.external_native_surface_cache { + resource_cache.destroy_compositor_surface(external_surface.native_surface_id) + } + + if let Some(backdrop_surface) = &self.backdrop_surface { + resource_cache.destroy_compositor_surface(backdrop_surface.id); + } + } + + /// Get the tile coordinates for a given rectangle. + fn get_tile_coords_for_rect( + &self, + rect: &PictureRect, + ) -> (TileOffset, TileOffset) { + // Get the tile coordinates in the picture space. + let mut p0 = TileOffset::new( + (rect.min.x / self.tile_size.width).floor() as i32, + (rect.min.y / self.tile_size.height).floor() as i32, + ); + + let mut p1 = TileOffset::new( + (rect.max.x / self.tile_size.width).ceil() as i32, + (rect.max.y / self.tile_size.height).ceil() as i32, + ); + + // Clamp the tile coordinates here to avoid looping over irrelevant tiles later on. + p0.x = clamp(p0.x, self.tile_bounds_p0.x, self.tile_bounds_p1.x); + p0.y = clamp(p0.y, self.tile_bounds_p0.y, self.tile_bounds_p1.y); + p1.x = clamp(p1.x, self.tile_bounds_p0.x, self.tile_bounds_p1.x); + p1.y = clamp(p1.y, self.tile_bounds_p0.y, self.tile_bounds_p1.y); + + (p0, p1) + } + + /// Update transforms, opacity, color bindings and tile rects. + pub fn pre_update( + &mut self, + pic_rect: PictureRect, + surface_index: SurfaceIndex, + frame_context: &FrameVisibilityContext, + frame_state: &mut FrameVisibilityState, + ) -> WorldRect { + self.surface_index = surface_index; + self.local_rect = pic_rect; + self.local_clip_rect = PictureRect::max_rect(); + self.deferred_dirty_tests.clear(); + + for sub_slice in &mut self.sub_slices { + sub_slice.reset(); + } + + // Reset the opaque rect + subpixel mode, as they are calculated + // during the prim dependency checks. + self.backdrop = BackdropInfo::empty(); + + // Calculate the screen rect in picture space, for later comparison against + // backdrops, and prims potentially covering backdrops. + let pic_to_world_mapper = SpaceMapper::new_with_target( + frame_context.root_spatial_node_index, + self.spatial_node_index, + frame_context.global_screen_world_rect, + frame_context.spatial_tree, + ); + self.screen_rect_in_pic_space = pic_to_world_mapper + .unmap(&frame_context.global_screen_world_rect) + .expect("unable to unmap screen rect"); + + // If there is a valid set of shared clips, build a clip chain instance for this, + // which will provide a local clip rect. This is useful for establishing things + // like whether the backdrop rect supplied by Gecko can be considered opaque. + if let Some(shared_clip_leaf_id) = self.shared_clip_leaf_id { + let map_local_to_surface = SpaceMapper::new( + self.spatial_node_index, + pic_rect, + ); + + frame_state.clip_store.set_active_clips( + self.spatial_node_index, + map_local_to_surface.ref_spatial_node_index, + shared_clip_leaf_id, + frame_context.spatial_tree, + &mut frame_state.data_stores.clip, + &frame_state.clip_tree, + ); + + let clip_chain_instance = frame_state.clip_store.build_clip_chain_instance( + pic_rect.cast_unit(), + &map_local_to_surface, + &pic_to_world_mapper, + frame_context.spatial_tree, + frame_state.gpu_cache, + frame_state.resource_cache, + frame_context.global_device_pixel_scale, + &frame_context.global_screen_world_rect, + &mut frame_state.data_stores.clip, + true, + ); + + // Ensure that if the entire picture cache is clipped out, the local + // clip rect is zero. This makes sure we don't register any occluders + // that are actually off-screen. + self.local_clip_rect = clip_chain_instance.map_or(PictureRect::zero(), |clip_chain_instance| { + clip_chain_instance.pic_coverage_rect + }); + } + + // Advance the current frame ID counter for this picture cache (must be done + // after any retained prev state is taken above). + self.frame_id.advance(); + + // Notify the spatial node comparer that a new frame has started, and the + // current reference spatial node for this tile cache. + self.spatial_node_comparer.next_frame(self.spatial_node_index); + + // At the start of the frame, step through each current compositor surface + // and mark it as unused. Later, this is used to free old compositor surfaces. + // TODO(gw): In future, we might make this more sophisticated - for example, + // retaining them for >1 frame if unused, or retaining them in some + // kind of pool to reduce future allocations. + for external_native_surface in self.external_native_surface_cache.values_mut() { + external_native_surface.used_this_frame = false; + } + + // Only evaluate what tile size to use fairly infrequently, so that we don't end + // up constantly invalidating and reallocating tiles if the picture rect size is + // changing near a threshold value. + if self.frames_until_size_eval == 0 || + self.tile_size_override != frame_context.config.tile_size_override { + + // Work out what size tile is appropriate for this picture cache. + let desired_tile_size = match frame_context.config.tile_size_override { + Some(tile_size_override) => { + tile_size_override + } + None => { + if self.slice_flags.contains(SliceFlags::IS_SCROLLBAR) { + if pic_rect.width() <= pic_rect.height() { + TILE_SIZE_SCROLLBAR_VERTICAL + } else { + TILE_SIZE_SCROLLBAR_HORIZONTAL + } + } else { + frame_state.resource_cache.picture_textures.default_tile_size() + } + } + }; + + // If the desired tile size has changed, then invalidate and drop any + // existing tiles. + if desired_tile_size != self.current_tile_size { + for sub_slice in &mut self.sub_slices { + // Destroy any native surfaces on the tiles that will be dropped due + // to resizing. + if let Some(native_surface) = sub_slice.native_surface.take() { + frame_state.resource_cache.destroy_compositor_surface(native_surface.opaque); + frame_state.resource_cache.destroy_compositor_surface(native_surface.alpha); + } + sub_slice.tiles.clear(); + } + self.tile_rect = TileRect::zero(); + self.current_tile_size = desired_tile_size; + } + + // Reset counter until next evaluating the desired tile size. This is an + // arbitrary value. + self.frames_until_size_eval = 120; + self.tile_size_override = frame_context.config.tile_size_override; + } + + // Get the complete scale-offset from local space to device space + let local_to_device = get_relative_scale_offset( + self.spatial_node_index, + frame_context.root_spatial_node_index, + frame_context.spatial_tree, + ); + + // Get the compositor transform, which depends on pinch-zoom mode + let mut surface_to_device = local_to_device; + + if frame_context.config.low_quality_pinch_zoom { + surface_to_device.scale.x /= self.current_raster_scale; + surface_to_device.scale.y /= self.current_raster_scale; + } else { + surface_to_device.scale.x = 1.0; + surface_to_device.scale.y = 1.0; + } + + // Use that compositor transform to calculate a relative local to surface + let local_to_surface = local_to_device.accumulate(&surface_to_device.inverse()); + + const EPSILON: f32 = 0.001; + let compositor_translation_changed = + !surface_to_device.offset.x.approx_eq_eps(&self.surface_to_device.offset.x, &EPSILON) || + !surface_to_device.offset.y.approx_eq_eps(&self.surface_to_device.offset.y, &EPSILON); + let compositor_scale_changed = + !surface_to_device.scale.x.approx_eq_eps(&self.surface_to_device.scale.x, &EPSILON) || + !surface_to_device.scale.y.approx_eq_eps(&self.surface_to_device.scale.y, &EPSILON); + let surface_scale_changed = + !local_to_surface.scale.x.approx_eq_eps(&self.local_to_surface.scale.x, &EPSILON) || + !local_to_surface.scale.y.approx_eq_eps(&self.local_to_surface.scale.y, &EPSILON); + + if compositor_translation_changed || + compositor_scale_changed || + surface_scale_changed || + frame_context.config.force_invalidation { + frame_state.composite_state.dirty_rects_are_valid = false; + } + + self.surface_to_device = surface_to_device; + self.local_to_surface = local_to_surface; + self.invalidate_all_tiles = surface_scale_changed || frame_context.config.force_invalidation; + + // Do a hacky diff of opacity binding values from the last frame. This is + // used later on during tile invalidation tests. + let current_properties = frame_context.scene_properties.float_properties(); + mem::swap(&mut self.opacity_bindings, &mut self.old_opacity_bindings); + + self.opacity_bindings.clear(); + for (id, value) in current_properties { + let changed = match self.old_opacity_bindings.get(id) { + Some(old_property) => !old_property.value.approx_eq(value), + None => true, + }; + self.opacity_bindings.insert(*id, OpacityBindingInfo { + value: *value, + changed, + }); + } + + // Do a hacky diff of color binding values from the last frame. This is + // used later on during tile invalidation tests. + let current_properties = frame_context.scene_properties.color_properties(); + mem::swap(&mut self.color_bindings, &mut self.old_color_bindings); + + self.color_bindings.clear(); + for (id, value) in current_properties { + let changed = match self.old_color_bindings.get(id) { + Some(old_property) => old_property.value != (*value).into(), + None => true, + }; + self.color_bindings.insert(*id, ColorBindingInfo { + value: (*value).into(), + changed, + }); + } + + let world_tile_size = WorldSize::new( + self.current_tile_size.width as f32 / frame_context.global_device_pixel_scale.0, + self.current_tile_size.height as f32 / frame_context.global_device_pixel_scale.0, + ); + + self.tile_size = PictureSize::new( + world_tile_size.width / self.local_to_surface.scale.x, + world_tile_size.height / self.local_to_surface.scale.y, + ); + + // Inflate the needed rect a bit, so that we retain tiles that we have drawn + // but have just recently gone off-screen. This means that we avoid re-drawing + // tiles if the user is scrolling up and down small amounts, at the cost of + // a bit of extra texture memory. + let desired_rect_in_pic_space = self.screen_rect_in_pic_space + .inflate(0.0, 1.0 * self.tile_size.height); + + let needed_rect_in_pic_space = desired_rect_in_pic_space + .intersection(&pic_rect) + .unwrap_or_else(Box2D::zero); + + let p0 = needed_rect_in_pic_space.min; + let p1 = needed_rect_in_pic_space.max; + + let x0 = (p0.x / self.tile_size.width).floor() as i32; + let x1 = (p1.x / self.tile_size.width).ceil() as i32; + + let y0 = (p0.y / self.tile_size.height).floor() as i32; + let y1 = (p1.y / self.tile_size.height).ceil() as i32; + + let new_tile_rect = TileRect { + min: TileOffset::new(x0, y0), + max: TileOffset::new(x1, y1), + }; + + // Determine whether the current bounds of the tile grid will exceed the + // bounds of the DC virtual surface, taking into account the current + // virtual offset. If so, we need to invalidate all tiles, and set up + // a new virtual offset, centered around the current tile grid. + + let virtual_surface_size = frame_context.config.compositor_kind.get_virtual_surface_size(); + // We only need to invalidate in this case if the underlying platform + // uses virtual surfaces. + if virtual_surface_size > 0 { + // Get the extremities of the tile grid after virtual offset is applied + let tx0 = self.virtual_offset.x + x0 * self.current_tile_size.width; + let ty0 = self.virtual_offset.y + y0 * self.current_tile_size.height; + let tx1 = self.virtual_offset.x + (x1+1) * self.current_tile_size.width; + let ty1 = self.virtual_offset.y + (y1+1) * self.current_tile_size.height; + + let need_new_virtual_offset = tx0 < 0 || + ty0 < 0 || + tx1 >= virtual_surface_size || + ty1 >= virtual_surface_size; + + if need_new_virtual_offset { + // Calculate a new virtual offset, centered around the middle of the + // current tile grid. This means we won't need to invalidate and get + // a new offset for a long time! + self.virtual_offset = DeviceIntPoint::new( + (virtual_surface_size/2) - ((x0 + x1) / 2) * self.current_tile_size.width, + (virtual_surface_size/2) - ((y0 + y1) / 2) * self.current_tile_size.height, + ); + + // Invalidate all native tile surfaces. They will be re-allocated next time + // they are scheduled to be rasterized. + for sub_slice in &mut self.sub_slices { + for tile in sub_slice.tiles.values_mut() { + if let Some(TileSurface::Texture { descriptor: SurfaceTextureDescriptor::Native { ref mut id, .. }, .. }) = tile.surface { + if let Some(id) = id.take() { + frame_state.resource_cache.destroy_compositor_tile(id); + tile.surface = None; + // Invalidate the entire tile to force a redraw. + // TODO(gw): Add a new invalidation reason for virtual offset changing + tile.invalidate(None, InvalidationReason::CompositorKindChanged); + } + } + } + + // Destroy the native virtual surfaces. They will be re-allocated next time a tile + // that references them is scheduled to draw. + if let Some(native_surface) = sub_slice.native_surface.take() { + frame_state.resource_cache.destroy_compositor_surface(native_surface.opaque); + frame_state.resource_cache.destroy_compositor_surface(native_surface.alpha); + } + } + } + } + + // Rebuild the tile grid if the picture cache rect has changed. + if new_tile_rect != self.tile_rect { + for sub_slice in &mut self.sub_slices { + let mut old_tiles = sub_slice.resize(new_tile_rect); + + // When old tiles that remain after the loop, dirty rects are not valid. + if !old_tiles.is_empty() { + frame_state.composite_state.dirty_rects_are_valid = false; + } + + // Any old tiles that remain after the loop above are going to be dropped. For + // simple composite mode, the texture cache handle will expire and be collected + // by the texture cache. For native compositor mode, we need to explicitly + // invoke a callback to the client to destroy that surface. + frame_state.composite_state.destroy_native_tiles( + old_tiles.values_mut(), + frame_state.resource_cache, + ); + } + } + + // This is duplicated information from tile_rect, but cached here to avoid + // redundant calculations during get_tile_coords_for_rect + self.tile_bounds_p0 = TileOffset::new(x0, y0); + self.tile_bounds_p1 = TileOffset::new(x1, y1); + self.tile_rect = new_tile_rect; + + let mut world_culling_rect = WorldRect::zero(); + + let mut ctx = TilePreUpdateContext { + pic_to_world_mapper, + background_color: self.background_color, + global_screen_world_rect: frame_context.global_screen_world_rect, + tile_size: self.tile_size, + frame_id: self.frame_id, + }; + + // Pre-update each tile + for sub_slice in &mut self.sub_slices { + for tile in sub_slice.tiles.values_mut() { + tile.pre_update(&ctx); + + // Only include the tiles that are currently in view into the world culling + // rect. This is a very important optimization for a couple of reasons: + // (1) Primitives that intersect with tiles in the grid that are not currently + // visible can be skipped from primitive preparation, clip chain building + // and tile dependency updates. + // (2) When we need to allocate an off-screen surface for a child picture (for + // example a CSS filter) we clip the size of the GPU surface to the world + // culling rect below (to ensure we draw enough of it to be sampled by any + // tiles that reference it). Making the world culling rect only affected + // by visible tiles (rather than the entire virtual tile display port) can + // result in allocating _much_ smaller GPU surfaces for cases where the + // true off-screen surface size is very large. + if tile.is_visible { + world_culling_rect = world_culling_rect.union(&tile.world_tile_rect); + } + } + + // The background color can only be applied to the first sub-slice. + ctx.background_color = None; + } + + // If compositor mode is changed, need to drop all incompatible tiles. + match frame_context.config.compositor_kind { + CompositorKind::Draw { .. } => { + for sub_slice in &mut self.sub_slices { + for tile in sub_slice.tiles.values_mut() { + if let Some(TileSurface::Texture { descriptor: SurfaceTextureDescriptor::Native { ref mut id, .. }, .. }) = tile.surface { + if let Some(id) = id.take() { + frame_state.resource_cache.destroy_compositor_tile(id); + } + tile.surface = None; + // Invalidate the entire tile to force a redraw. + tile.invalidate(None, InvalidationReason::CompositorKindChanged); + } + } + + if let Some(native_surface) = sub_slice.native_surface.take() { + frame_state.resource_cache.destroy_compositor_surface(native_surface.opaque); + frame_state.resource_cache.destroy_compositor_surface(native_surface.alpha); + } + } + + for (_, external_surface) in self.external_native_surface_cache.drain() { + frame_state.resource_cache.destroy_compositor_surface(external_surface.native_surface_id) + } + } + CompositorKind::Native { .. } => { + // This could hit even when compositor mode is not changed, + // then we need to check if there are incompatible tiles. + for sub_slice in &mut self.sub_slices { + for tile in sub_slice.tiles.values_mut() { + if let Some(TileSurface::Texture { descriptor: SurfaceTextureDescriptor::TextureCache { .. }, .. }) = tile.surface { + tile.surface = None; + // Invalidate the entire tile to force a redraw. + tile.invalidate(None, InvalidationReason::CompositorKindChanged); + } + } + } + } + } + + world_culling_rect + } + + fn can_promote_to_surface( + &mut self, + flags: PrimitiveFlags, + prim_clip_chain: &ClipChainInstance, + prim_spatial_node_index: SpatialNodeIndex, + is_root_tile_cache: bool, + sub_slice_index: usize, + frame_context: &FrameVisibilityContext, + ) -> SurfacePromotionResult { + // Check if this primitive _wants_ to be promoted to a compositor surface. + if !flags.contains(PrimitiveFlags::PREFER_COMPOSITOR_SURFACE) { + return SurfacePromotionResult::Failed; + } + + // For now, only support a small (arbitrary) number of compositor surfaces. + if sub_slice_index == MAX_COMPOSITOR_SURFACES { + return SurfacePromotionResult::Failed; + } + + // If a complex clip is being applied to this primitive, it can't be + // promoted directly to a compositor surface (we might be able to + // do this in limited cases in future, some native compositors do + // support rounded rect clips, for example) + if prim_clip_chain.needs_mask { + return SurfacePromotionResult::Failed; + } + + // If not on the root picture cache, it has some kind of + // complex effect (such as a filter, mix-blend-mode or 3d transform). + if !is_root_tile_cache { + return SurfacePromotionResult::Failed; + } + + let mapper : SpaceMapper<PicturePixel, WorldPixel> = SpaceMapper::new_with_target( + frame_context.root_spatial_node_index, + prim_spatial_node_index, + frame_context.global_screen_world_rect, + &frame_context.spatial_tree); + let transform = mapper.get_transform(); + if !transform.is_2d_scale_translation() { + return SurfacePromotionResult::Failed; + } + + if self.slice_flags.contains(SliceFlags::IS_ATOMIC) { + return SurfacePromotionResult::Failed; + } + + SurfacePromotionResult::Success + } + + fn setup_compositor_surfaces_yuv( + &mut self, + sub_slice_index: usize, + prim_info: &mut PrimitiveDependencyInfo, + flags: PrimitiveFlags, + local_prim_rect: LayoutRect, + prim_spatial_node_index: SpatialNodeIndex, + pic_coverage_rect: PictureRect, + frame_context: &FrameVisibilityContext, + image_dependencies: &[ImageDependency;3], + api_keys: &[ImageKey; 3], + resource_cache: &mut ResourceCache, + composite_state: &mut CompositeState, + gpu_cache: &mut GpuCache, + image_rendering: ImageRendering, + color_depth: ColorDepth, + color_space: YuvRangedColorSpace, + format: YuvFormat, + ) -> bool { + for &key in api_keys { + if key != ImageKey::DUMMY { + // TODO: See comment in setup_compositor_surfaces_rgb. + resource_cache.request_image(ImageRequest { + key, + rendering: image_rendering, + tile: None, + }, + gpu_cache, + ); + } + } + + self.setup_compositor_surfaces_impl( + sub_slice_index, + prim_info, + flags, + local_prim_rect, + prim_spatial_node_index, + pic_coverage_rect, + frame_context, + ExternalSurfaceDependency::Yuv { + image_dependencies: *image_dependencies, + color_space, + format, + channel_bit_depth: color_depth.bit_depth(), + }, + api_keys, + resource_cache, + composite_state, + image_rendering, + true, + ) + } + + fn setup_compositor_surfaces_rgb( + &mut self, + sub_slice_index: usize, + prim_info: &mut PrimitiveDependencyInfo, + flags: PrimitiveFlags, + local_prim_rect: LayoutRect, + prim_spatial_node_index: SpatialNodeIndex, + pic_coverage_rect: PictureRect, + frame_context: &FrameVisibilityContext, + image_dependency: ImageDependency, + api_key: ImageKey, + resource_cache: &mut ResourceCache, + composite_state: &mut CompositeState, + gpu_cache: &mut GpuCache, + image_rendering: ImageRendering, + ) -> bool { + let mut api_keys = [ImageKey::DUMMY; 3]; + api_keys[0] = api_key; + + // TODO: The picture compositing code requires images promoted + // into their own picture cache slices to be requested every + // frame even if they are not visible. However the image updates + // are only reached on the prepare pass for visible primitives. + // So we make sure to trigger an image request when promoting + // the image here. + resource_cache.request_image(ImageRequest { + key: api_key, + rendering: image_rendering, + tile: None, + }, + gpu_cache, + ); + + let is_opaque = resource_cache.get_image_properties(api_key) + .map_or(false, |properties| properties.descriptor.is_opaque()); + + self.setup_compositor_surfaces_impl( + sub_slice_index, + prim_info, + flags, + local_prim_rect, + prim_spatial_node_index, + pic_coverage_rect, + frame_context, + ExternalSurfaceDependency::Rgb { + image_dependency, + }, + &api_keys, + resource_cache, + composite_state, + image_rendering, + is_opaque, + ) + } + + // returns false if composition is not available for this surface, + // and the non-compositor path should be used to draw it instead. + fn setup_compositor_surfaces_impl( + &mut self, + sub_slice_index: usize, + prim_info: &mut PrimitiveDependencyInfo, + flags: PrimitiveFlags, + local_prim_rect: LayoutRect, + prim_spatial_node_index: SpatialNodeIndex, + pic_coverage_rect: PictureRect, + frame_context: &FrameVisibilityContext, + dependency: ExternalSurfaceDependency, + api_keys: &[ImageKey; 3], + resource_cache: &mut ResourceCache, + composite_state: &mut CompositeState, + image_rendering: ImageRendering, + is_opaque: bool, + ) -> bool { + let map_local_to_surface = SpaceMapper::new_with_target( + self.spatial_node_index, + prim_spatial_node_index, + self.local_rect, + frame_context.spatial_tree, + ); + + // Map the primitive local rect into picture space. + let prim_rect = match map_local_to_surface.map(&local_prim_rect) { + Some(rect) => rect, + None => return true, + }; + + // If the rect is invalid, no need to create dependencies. + if prim_rect.is_empty() { + return true; + } + + let pic_to_world_mapper = SpaceMapper::new_with_target( + frame_context.root_spatial_node_index, + self.spatial_node_index, + frame_context.global_screen_world_rect, + frame_context.spatial_tree, + ); + + let world_clip_rect = pic_to_world_mapper + .map(&prim_info.prim_clip_box) + .expect("bug: unable to map clip to world space"); + + let is_visible = world_clip_rect.intersects(&frame_context.global_screen_world_rect); + if !is_visible { + return true; + } + + let prim_offset = ScaleOffset::from_offset(local_prim_rect.min.to_vector().cast_unit()); + + let local_prim_to_device = get_relative_scale_offset( + prim_spatial_node_index, + frame_context.root_spatial_node_index, + frame_context.spatial_tree, + ); + + let normalized_prim_to_device = prim_offset.accumulate(&local_prim_to_device); + + let local_to_surface = ScaleOffset::identity(); + let surface_to_device = normalized_prim_to_device; + + // If this primitive is an external image, and supports being used + // directly by a native compositor, then lookup the external image id + // so we can pass that through. + let mut external_image_id = if flags.contains(PrimitiveFlags::SUPPORTS_EXTERNAL_COMPOSITOR_SURFACE) + && image_rendering == ImageRendering::Auto { + resource_cache.get_image_properties(api_keys[0]) + .and_then(|properties| properties.external_image) + .and_then(|image| Some(image.id)) + } else { + None + }; + + + if let CompositorKind::Native { capabilities, .. } = composite_state.compositor_kind { + if external_image_id.is_some() && + !capabilities.supports_external_compositor_surface_negative_scaling && + (surface_to_device.scale.x < 0.0 || surface_to_device.scale.y < 0.0) { + external_image_id = None; + } + } + + let compositor_transform_index = composite_state.register_transform( + local_to_surface, + surface_to_device, + ); + + let surface_size = composite_state.get_surface_rect( + &local_prim_rect, + &local_prim_rect, + compositor_transform_index, + ).size(); + + let clip_rect = (world_clip_rect * frame_context.global_device_pixel_scale).round(); + + if surface_size.width >= MAX_COMPOSITOR_SURFACES_SIZE || + surface_size.height >= MAX_COMPOSITOR_SURFACES_SIZE { + return false; + } + + // When using native compositing, we need to find an existing native surface + // handle to use, or allocate a new one. For existing native surfaces, we can + // also determine whether this needs to be updated, depending on whether the + // image generation(s) of the planes have changed since last composite. + let (native_surface_id, update_params) = match composite_state.compositor_kind { + CompositorKind::Draw { .. } => { + (None, None) + } + CompositorKind::Native { .. } => { + let native_surface_size = surface_size.to_i32(); + + let key = ExternalNativeSurfaceKey { + image_keys: *api_keys, + size: if external_image_id.is_some() { None } else { Some(native_surface_size) }, + }; + + let native_surface = self.external_native_surface_cache + .entry(key) + .or_insert_with(|| { + // No existing surface, so allocate a new compositor surface. + let native_surface_id = match external_image_id { + Some(_external_image) => { + // If we have a suitable external image, then create an external + // surface to attach to. + resource_cache.create_compositor_external_surface(is_opaque) + } + None => { + // Otherwise create a normal compositor surface and a single + // compositor tile that covers the entire surface. + let native_surface_id = + resource_cache.create_compositor_surface( + DeviceIntPoint::zero(), + native_surface_size, + is_opaque, + ); + + let tile_id = NativeTileId { + surface_id: native_surface_id, + x: 0, + y: 0, + }; + resource_cache.create_compositor_tile(tile_id); + + native_surface_id + } + }; + + ExternalNativeSurface { + used_this_frame: true, + native_surface_id, + image_dependencies: [ImageDependency::INVALID; 3], + } + }); + + // Mark that the surface is referenced this frame so that the + // backing native surface handle isn't freed. + native_surface.used_this_frame = true; + + let update_params = match external_image_id { + Some(external_image) => { + // If this is an external image surface, then there's no update + // to be done. Just attach the current external image to the surface + // and we're done. + resource_cache.attach_compositor_external_image( + native_surface.native_surface_id, + external_image, + ); + None + } + None => { + // If the image dependencies match, there is no need to update + // the backing native surface. + match dependency { + ExternalSurfaceDependency::Yuv{ image_dependencies, .. } => { + if image_dependencies == native_surface.image_dependencies { + None + } else { + Some(native_surface_size) + } + }, + ExternalSurfaceDependency::Rgb{ image_dependency, .. } => { + if image_dependency == native_surface.image_dependencies[0] { + None + } else { + Some(native_surface_size) + } + }, + } + } + }; + + (Some(native_surface.native_surface_id), update_params) + } + }; + + // For compositor surfaces, if we didn't find an earlier sub-slice to add to, + // we know we can append to the current slice. + assert!(sub_slice_index < self.sub_slices.len() - 1); + let sub_slice = &mut self.sub_slices[sub_slice_index]; + + // Each compositor surface allocates a unique z-id + sub_slice.compositor_surfaces.push(CompositorSurface { + prohibited_rect: pic_coverage_rect, + is_opaque, + descriptor: ExternalSurfaceDescriptor { + local_surface_size: local_prim_rect.size(), + local_rect: prim_rect, + local_clip_rect: prim_info.prim_clip_box, + dependency, + image_rendering, + clip_rect, + transform_index: compositor_transform_index, + z_id: ZBufferId::invalid(), + native_surface_id, + update_params, + }, + }); + + true + } + + /// Push an estimated rect for an off-screen surface during dependency updates. This is + /// a workaround / hack that allows the picture cache code to know when it should be + /// processing primitive dependencies as a single atomic unit. In future, we aim to remove + /// this hack by having the primitive dependencies stored _within_ each owning picture. + /// This is part of the work required to support child picture caching anyway! + pub fn push_surface( + &mut self, + estimated_local_rect: LayoutRect, + surface_spatial_node_index: SpatialNodeIndex, + spatial_tree: &SpatialTree, + ) { + // Only need to evaluate sub-slice regions if we have compositor surfaces present + if self.current_surface_traversal_depth == 0 && self.sub_slices.len() > 1 { + let map_local_to_surface = SpaceMapper::new_with_target( + self.spatial_node_index, + surface_spatial_node_index, + self.local_rect, + spatial_tree, + ); + + if let Some(pic_rect) = map_local_to_surface.map(&estimated_local_rect) { + // Find the first sub-slice we can add this primitive to (we want to add + // prims to the primary surface if possible, so they get subpixel AA). + for sub_slice in &mut self.sub_slices { + let mut intersects_prohibited_region = false; + + for surface in &mut sub_slice.compositor_surfaces { + if pic_rect.intersects(&surface.prohibited_rect) { + surface.prohibited_rect = surface.prohibited_rect.union(&pic_rect); + + intersects_prohibited_region = true; + } + } + + if !intersects_prohibited_region { + break; + } + } + } + } + + self.current_surface_traversal_depth += 1; + } + + /// Pop an off-screen surface off the stack during dependency updates + pub fn pop_surface(&mut self) { + self.current_surface_traversal_depth -= 1; + } + + /// Update the dependencies for each tile for a given primitive instance. + pub fn update_prim_dependencies( + &mut self, + prim_instance: &mut PrimitiveInstance, + prim_spatial_node_index: SpatialNodeIndex, + local_prim_rect: LayoutRect, + frame_context: &FrameVisibilityContext, + data_stores: &DataStores, + clip_store: &ClipStore, + pictures: &[PicturePrimitive], + resource_cache: &mut ResourceCache, + color_bindings: &ColorBindingStorage, + surface_stack: &[(PictureIndex, SurfaceIndex)], + composite_state: &mut CompositeState, + gpu_cache: &mut GpuCache, + scratch: &mut PrimitiveScratchBuffer, + is_root_tile_cache: bool, + surfaces: &mut [SurfaceInfo], + ) { + // This primitive exists on the last element on the current surface stack. + profile_scope!("update_prim_dependencies"); + let prim_surface_index = surface_stack.last().unwrap().1; + let prim_clip_chain = &prim_instance.vis.clip_chain; + + // Accumulate the exact (clipped) local rect in to the parent surface + let mut surface = &mut surfaces[prim_surface_index.0]; + surface.clipped_local_rect = surface.clipped_local_rect.union(&prim_clip_chain.pic_coverage_rect); + + // If the primitive is directly drawn onto this picture cache surface, then + // the pic_coverage_rect is in the same space. If not, we need to map it from + // the surface space into the picture cache space. + let on_picture_surface = prim_surface_index == self.surface_index; + let pic_coverage_rect = if on_picture_surface { + prim_clip_chain.pic_coverage_rect + } else { + // We want to get the rect in the tile cache surface space that this primitive + // occupies, in order to enable correct invalidation regions. Each surface + // that exists in the chain between this primitive and the tile cache surface + // may have an arbitrary inflation factor (for example, in the case of a series + // of nested blur elements). To account for this, step through the current + // surface stack, mapping the primitive rect into each surface space, including + // the inflation factor from each intermediate surface. + let mut current_pic_coverage_rect = prim_clip_chain.pic_coverage_rect; + let mut current_spatial_node_index = surfaces[prim_surface_index.0] + .surface_spatial_node_index; + + for (pic_index, surface_index) in surface_stack.iter().rev() { + let surface = &surfaces[surface_index.0]; + let pic = &pictures[pic_index.0]; + + let map_local_to_surface = SpaceMapper::new_with_target( + surface.surface_spatial_node_index, + current_spatial_node_index, + surface.unclipped_local_rect, + frame_context.spatial_tree, + ); + + // Map the rect into the parent surface, and inflate if this surface requires + // it. If the rect can't be mapping (e.g. due to an invalid transform) then + // just bail out from the dependencies and cull this primitive. + current_pic_coverage_rect = match map_local_to_surface.map(¤t_pic_coverage_rect) { + Some(rect) => { + // TODO(gw): The casts here are a hack. We have some interface inconsistencies + // between layout/picture rects which don't really work with the + // current unit system, since sometimes the local rect of a picture + // is a LayoutRect, and sometimes it's a PictureRect. Consider how + // we can improve this? + pic.composite_mode.as_ref().unwrap().get_coverage( + surface, + Some(rect.cast_unit()), + ).cast_unit() + } + None => { + return; + } + }; + + current_spatial_node_index = surface.surface_spatial_node_index; + } + + current_pic_coverage_rect + }; + + // Get the tile coordinates in the picture space. + let (p0, p1) = self.get_tile_coords_for_rect(&pic_coverage_rect); + + // If the primitive is outside the tiling rects, it's known to not + // be visible. + if p0.x == p1.x || p0.y == p1.y { + return; + } + + // Build the list of resources that this primitive has dependencies on. + let mut prim_info = PrimitiveDependencyInfo::new( + prim_instance.uid(), + pic_coverage_rect, + ); + + let mut sub_slice_index = self.sub_slices.len() - 1; + + // Only need to evaluate sub-slice regions if we have compositor surfaces present + if sub_slice_index > 0 { + // Find the first sub-slice we can add this primitive to (we want to add + // prims to the primary surface if possible, so they get subpixel AA). + for (i, sub_slice) in self.sub_slices.iter_mut().enumerate() { + let mut intersects_prohibited_region = false; + + for surface in &mut sub_slice.compositor_surfaces { + if pic_coverage_rect.intersects(&surface.prohibited_rect) { + surface.prohibited_rect = surface.prohibited_rect.union(&pic_coverage_rect); + + intersects_prohibited_region = true; + } + } + + if !intersects_prohibited_region { + sub_slice_index = i; + break; + } + } + } + + // Include the prim spatial node, if differs relative to cache root. + if prim_spatial_node_index != self.spatial_node_index { + prim_info.spatial_nodes.push(prim_spatial_node_index); + } + + // If there was a clip chain, add any clip dependencies to the list for this tile. + let clip_instances = &clip_store + .clip_node_instances[prim_clip_chain.clips_range.to_range()]; + for clip_instance in clip_instances { + let clip = &data_stores.clip[clip_instance.handle]; + + prim_info.clips.push(clip_instance.handle.uid()); + + // If the clip has the same spatial node, the relative transform + // will always be the same, so there's no need to depend on it. + if clip.item.spatial_node_index != self.spatial_node_index + && !prim_info.spatial_nodes.contains(&clip.item.spatial_node_index) { + prim_info.spatial_nodes.push(clip.item.spatial_node_index); + } + } + + // Certain primitives may select themselves to be a backdrop candidate, which is + // then applied below. + let mut backdrop_candidate = None; + + // For pictures, we don't (yet) know the valid clip rect, so we can't correctly + // use it to calculate the local bounding rect for the tiles. If we include them + // then we may calculate a bounding rect that is too large, since it won't include + // the clip bounds of the picture. Excluding them from the bounding rect here + // fixes any correctness issues (the clips themselves are considered when we + // consider the bounds of the primitives that are *children* of the picture), + // however it does potentially result in some un-necessary invalidations of a + // tile (in cases where the picture local rect affects the tile, but the clip + // rect eventually means it doesn't affect that tile). + // TODO(gw): Get picture clips earlier (during the initial picture traversal + // pass) so that we can calculate these correctly. + match prim_instance.kind { + PrimitiveInstanceKind::Picture { pic_index,.. } => { + // Pictures can depend on animated opacity bindings. + let pic = &pictures[pic_index.0]; + if let Some(PictureCompositeMode::Filter(Filter::Opacity(binding, _))) = pic.composite_mode { + prim_info.opacity_bindings.push(binding.into()); + } + } + PrimitiveInstanceKind::Rectangle { data_handle, color_binding_index, .. } => { + // Rectangles can only form a backdrop candidate if they are known opaque. + // TODO(gw): We could resolve the opacity binding here, but the common + // case for background rects is that they don't have animated opacity. + let color = match data_stores.prim[data_handle].kind { + PrimitiveTemplateKind::Rectangle { color, .. } => { + frame_context.scene_properties.resolve_color(&color) + } + _ => unreachable!(), + }; + if color.a >= 1.0 { + backdrop_candidate = Some(BackdropInfo { + opaque_rect: pic_coverage_rect, + spanning_opaque_color: None, + kind: Some(BackdropKind::Color { color }), + backdrop_rect: pic_coverage_rect, + }); + } + + if color_binding_index != ColorBindingIndex::INVALID { + prim_info.color_binding = Some(color_bindings[color_binding_index].into()); + } + } + PrimitiveInstanceKind::Image { data_handle, ref mut is_compositor_surface, .. } => { + let image_key = &data_stores.image[data_handle]; + let image_data = &image_key.kind; + + let mut promote_to_surface = false; + match self.can_promote_to_surface(image_key.common.flags, + prim_clip_chain, + prim_spatial_node_index, + is_root_tile_cache, + sub_slice_index, + frame_context) { + SurfacePromotionResult::Failed => { + } + SurfacePromotionResult::Success => { + promote_to_surface = true; + } + } + + // Native OS compositors (DC and CA, at least) support premultiplied alpha + // only. If we have an image that's not pre-multiplied alpha, we can't promote it. + if image_data.alpha_type == AlphaType::Alpha { + promote_to_surface = false; + } + + if let Some(image_properties) = resource_cache.get_image_properties(image_data.key) { + // For an image to be a possible opaque backdrop, it must: + // - Have a valid, opaque image descriptor + // - Not use tiling (since they can fail to draw) + // - Not having any spacing / padding + // - Have opaque alpha in the instance (flattened) color + if image_properties.descriptor.is_opaque() && + image_properties.tiling.is_none() && + image_data.tile_spacing == LayoutSize::zero() && + image_data.color.a >= 1.0 { + backdrop_candidate = Some(BackdropInfo { + opaque_rect: pic_coverage_rect, + spanning_opaque_color: None, + kind: None, + backdrop_rect: PictureRect::zero(), + }); + } + } + + if promote_to_surface { + promote_to_surface = self.setup_compositor_surfaces_rgb( + sub_slice_index, + &mut prim_info, + image_key.common.flags, + local_prim_rect, + prim_spatial_node_index, + pic_coverage_rect, + frame_context, + ImageDependency { + key: image_data.key, + generation: resource_cache.get_image_generation(image_data.key), + }, + image_data.key, + resource_cache, + composite_state, + gpu_cache, + image_data.image_rendering, + ); + } + + *is_compositor_surface = promote_to_surface; + + if promote_to_surface { + prim_instance.vis.state = VisibilityState::Culled; + return; + } else { + prim_info.images.push(ImageDependency { + key: image_data.key, + generation: resource_cache.get_image_generation(image_data.key), + }); + } + } + PrimitiveInstanceKind::YuvImage { data_handle, ref mut is_compositor_surface, .. } => { + let prim_data = &data_stores.yuv_image[data_handle]; + let mut promote_to_surface = match self.can_promote_to_surface( + prim_data.common.flags, + prim_clip_chain, + prim_spatial_node_index, + is_root_tile_cache, + sub_slice_index, + frame_context) { + SurfacePromotionResult::Failed => false, + SurfacePromotionResult::Success => true, + }; + + // TODO(gw): When we support RGBA images for external surfaces, we also + // need to check if opaque (YUV images are implicitly opaque). + + // If this primitive is being promoted to a surface, construct an external + // surface descriptor for use later during batching and compositing. We only + // add the image keys for this primitive as a dependency if this is _not_ + // a promoted surface, since we don't want the tiles to invalidate when the + // video content changes, if it's a compositor surface! + if promote_to_surface { + // Build dependency for each YUV plane, with current image generation for + // later detection of when the composited surface has changed. + let mut image_dependencies = [ImageDependency::INVALID; 3]; + for (key, dep) in prim_data.kind.yuv_key.iter().cloned().zip(image_dependencies.iter_mut()) { + *dep = ImageDependency { + key, + generation: resource_cache.get_image_generation(key), + } + } + + promote_to_surface = self.setup_compositor_surfaces_yuv( + sub_slice_index, + &mut prim_info, + prim_data.common.flags, + local_prim_rect, + prim_spatial_node_index, + pic_coverage_rect, + frame_context, + &image_dependencies, + &prim_data.kind.yuv_key, + resource_cache, + composite_state, + gpu_cache, + prim_data.kind.image_rendering, + prim_data.kind.color_depth, + prim_data.kind.color_space.with_range(prim_data.kind.color_range), + prim_data.kind.format, + ); + } + + // Store on the YUV primitive instance whether this is a promoted surface. + // This is used by the batching code to determine whether to draw the + // image to the content tiles, or just a transparent z-write. + *is_compositor_surface = promote_to_surface; + + if promote_to_surface { + prim_instance.vis.state = VisibilityState::Culled; + return; + } else { + prim_info.images.extend( + prim_data.kind.yuv_key.iter().map(|key| { + ImageDependency { + key: *key, + generation: resource_cache.get_image_generation(*key), + } + }) + ); + } + } + PrimitiveInstanceKind::ImageBorder { data_handle, .. } => { + let border_data = &data_stores.image_border[data_handle].kind; + prim_info.images.push(ImageDependency { + key: border_data.request.key, + generation: resource_cache.get_image_generation(border_data.request.key), + }); + } + PrimitiveInstanceKind::Clear { .. } => { + backdrop_candidate = Some(BackdropInfo { + opaque_rect: pic_coverage_rect, + spanning_opaque_color: None, + kind: Some(BackdropKind::Clear), + backdrop_rect: pic_coverage_rect, + }); + } + PrimitiveInstanceKind::LinearGradient { data_handle, .. } + | PrimitiveInstanceKind::CachedLinearGradient { data_handle, .. } => { + let gradient_data = &data_stores.linear_grad[data_handle]; + if gradient_data.stops_opacity.is_opaque + && gradient_data.tile_spacing == LayoutSize::zero() + { + backdrop_candidate = Some(BackdropInfo { + opaque_rect: pic_coverage_rect, + spanning_opaque_color: None, + kind: None, + backdrop_rect: PictureRect::zero(), + }); + } + } + PrimitiveInstanceKind::ConicGradient { data_handle, .. } => { + let gradient_data = &data_stores.conic_grad[data_handle]; + if gradient_data.stops_opacity.is_opaque + && gradient_data.tile_spacing == LayoutSize::zero() + { + backdrop_candidate = Some(BackdropInfo { + opaque_rect: pic_coverage_rect, + spanning_opaque_color: None, + kind: None, + backdrop_rect: PictureRect::zero(), + }); + } + } + PrimitiveInstanceKind::RadialGradient { data_handle, .. } => { + let gradient_data = &data_stores.radial_grad[data_handle]; + if gradient_data.stops_opacity.is_opaque + && gradient_data.tile_spacing == LayoutSize::zero() + { + backdrop_candidate = Some(BackdropInfo { + opaque_rect: pic_coverage_rect, + spanning_opaque_color: None, + kind: None, + backdrop_rect: PictureRect::zero(), + }); + } + } + PrimitiveInstanceKind::BackdropCapture { .. } => {} + PrimitiveInstanceKind::BackdropRender { pic_index, .. } => { + // If the area that the backdrop covers in the space of the surface it draws on + // is empty, skip any sub-graph processing. This is not just a performance win, + // it also ensures that we don't do a deferred dirty test that invalidates a tile + // even if the tile isn't actually dirty, which can cause panics later in the + // WR pipeline. + if !pic_coverage_rect.is_empty() { + // Mark that we need the sub-graph this render depends on so that + // we don't skip it during the prepare pass + scratch.required_sub_graphs.insert(pic_index); + + // If this is a sub-graph, register the bounds on any affected tiles + // so we know how much to expand the content tile by. + + // Implicitly, we know that any slice with a sub-graph disables compositor + // surface promotion, so sub_slice_index will always be 0. + debug_assert_eq!(sub_slice_index, 0); + let sub_slice = &mut self.sub_slices[sub_slice_index]; + + let mut surface_info = Vec::new(); + for (pic_index, surface_index) in surface_stack.iter().rev() { + let pic = &pictures[pic_index.0]; + surface_info.push((pic.composite_mode.as_ref().unwrap().clone(), *surface_index)); + } + + for y in p0.y .. p1.y { + for x in p0.x .. p1.x { + let key = TileOffset::new(x, y); + let tile = sub_slice.tiles.get_mut(&key).expect("bug: no tile"); + tile.sub_graphs.push((pic_coverage_rect, surface_info.clone())); + } + } + + // For backdrop-filter, we need to check if any of the dirty rects + // in tiles that are affected by the filter primitive are dirty. + self.deferred_dirty_tests.push(DeferredDirtyTest { + tile_rect: TileRect::new(p0, p1), + prim_rect: pic_coverage_rect, + }); + } + } + PrimitiveInstanceKind::LineDecoration { .. } | + PrimitiveInstanceKind::NormalBorder { .. } | + PrimitiveInstanceKind::TextRun { .. } => { + // These don't contribute dependencies + } + }; + + // Calculate the screen rect in local space. When we calculate backdrops, we + // care only that they cover the visible rect, and don't have any overlapping + // prims in the visible rect. + let visible_local_rect = self.local_rect.intersection(&self.screen_rect_in_pic_space).unwrap_or_default(); + if pic_coverage_rect.intersects(&visible_local_rect) { + self.found_prims_after_backdrop = true; + } + + // If this primitive considers itself a backdrop candidate, apply further + // checks to see if it matches all conditions to be a backdrop. + let mut vis_flags = PrimitiveVisibilityFlags::empty(); + let sub_slice = &mut self.sub_slices[sub_slice_index]; + if let Some(mut backdrop_candidate) = backdrop_candidate { + // Update whether the surface that this primitive exists on + // can be considered opaque. Any backdrop kind other than + // a clear primitive (e.g. color, gradient, image) can be + // considered. + match backdrop_candidate.kind { + Some(BackdropKind::Color { .. }) | None => { + let surface = &mut surfaces[prim_surface_index.0]; + + let is_same_coord_system = frame_context.spatial_tree.is_matching_coord_system( + prim_spatial_node_index, + surface.surface_spatial_node_index, + ); + + // To be an opaque backdrop, it must: + // - Be the same coordinate system (axis-aligned) + // - Have no clip mask + // - Have a rect that covers the surface local rect + if is_same_coord_system && + !prim_clip_chain.needs_mask && + prim_clip_chain.pic_coverage_rect.contains_box(&surface.unclipped_local_rect) + { + // Note that we use `prim_clip_chain.pic_clip_rect` here rather + // than `backdrop_candidate.opaque_rect`. The former is in the + // local space of the surface, the latter is in the local space + // of the top level tile-cache. + surface.is_opaque = true; + } + } + Some(BackdropKind::Clear) => {} + } + + let is_suitable_backdrop = match backdrop_candidate.kind { + Some(BackdropKind::Clear) => { + // Clear prims are special - they always end up in their own slice, + // and always set the backdrop. In future, we hope to completely + // remove clear prims, since they don't integrate with the compositing + // system cleanly. + true + } + Some(BackdropKind::Color { .. }) | None => { + // Check a number of conditions to see if we can consider this + // primitive as an opaque backdrop rect. Several of these are conservative + // checks and could be relaxed in future. However, these checks + // are quick and capture the common cases of background rects and images. + // Specifically, we currently require: + // - The primitive is on the main picture cache surface. + // - Same coord system as picture cache (ensures rects are axis-aligned). + // - No clip masks exist. + let same_coord_system = frame_context.spatial_tree.is_matching_coord_system( + prim_spatial_node_index, + self.spatial_node_index, + ); + + same_coord_system && on_picture_surface + } + }; + + if sub_slice_index == 0 && + is_suitable_backdrop && + sub_slice.compositor_surfaces.is_empty() { + + // If the backdrop candidate has a clip-mask, try to extract an opaque inner + // rect that is safe to use for subpixel rendering + if prim_clip_chain.needs_mask { + backdrop_candidate.opaque_rect = clip_store + .get_inner_rect_for_clip_chain( + prim_clip_chain, + &data_stores.clip, + frame_context.spatial_tree, + ) + .unwrap_or(PictureRect::zero()); + } + + // We set the backdrop opaque_rect here, indicating the coverage area, which + // is useful for calculate_subpixel_mode. We will only set the backdrop kind + // if it covers the visible rect. + if backdrop_candidate.opaque_rect.contains_box(&self.backdrop.opaque_rect) { + self.backdrop.opaque_rect = backdrop_candidate.opaque_rect; + } + + if let Some(kind) = backdrop_candidate.kind { + if backdrop_candidate.opaque_rect.contains_box(&visible_local_rect) { + self.found_prims_after_backdrop = false; + self.backdrop.kind = Some(kind); + self.backdrop.backdrop_rect = backdrop_candidate.opaque_rect; + + // If we have a color backdrop that spans the entire local rect, mark + // the visibility flags of the primitive so it is skipped during batching + // (and also clears any previous primitives). Additionally, update our + // background color to match the backdrop color, which will ensure that + // our tiles are cleared to this color. + if let BackdropKind::Color { color } = kind { + if backdrop_candidate.opaque_rect.contains_box(&self.local_rect) { + vis_flags |= PrimitiveVisibilityFlags::IS_BACKDROP; + self.backdrop.spanning_opaque_color = Some(color); + } + } + } + } + } + } + + // Record any new spatial nodes in the used list. + for spatial_node_index in &prim_info.spatial_nodes { + self.spatial_node_comparer.register_used_transform( + *spatial_node_index, + self.frame_id, + frame_context.spatial_tree, + ); + } + + // Normalize the tile coordinates before adding to tile dependencies. + // For each affected tile, mark any of the primitive dependencies. + for y in p0.y .. p1.y { + for x in p0.x .. p1.x { + // TODO(gw): Convert to 2d array temporarily to avoid hash lookups per-tile? + let key = TileOffset::new(x, y); + let tile = sub_slice.tiles.get_mut(&key).expect("bug: no tile"); + + tile.add_prim_dependency(&prim_info); + } + } + + prim_instance.vis.state = VisibilityState::Visible { + vis_flags, + sub_slice_index: SubSliceIndex::new(sub_slice_index), + }; + } + + /// Print debug information about this picture cache to a tree printer. + fn print(&self) { + // TODO(gw): This initial implementation is very basic - just printing + // the picture cache state to stdout. In future, we can + // make this dump each frame to a file, and produce a report + // stating which frames had invalidations. This will allow + // diff'ing the invalidation states in a visual tool. + let mut pt = PrintTree::new("Picture Cache"); + + pt.new_level(format!("Slice {:?}", self.slice)); + + pt.add_item(format!("background_color: {:?}", self.background_color)); + + for (sub_slice_index, sub_slice) in self.sub_slices.iter().enumerate() { + pt.new_level(format!("SubSlice {:?}", sub_slice_index)); + + for y in self.tile_bounds_p0.y .. self.tile_bounds_p1.y { + for x in self.tile_bounds_p0.x .. self.tile_bounds_p1.x { + let key = TileOffset::new(x, y); + let tile = &sub_slice.tiles[&key]; + tile.print(&mut pt); + } + } + + pt.end_level(); + } + + pt.end_level(); + } + + fn calculate_subpixel_mode(&self) -> SubpixelMode { + let has_opaque_bg_color = self.background_color.map_or(false, |c| c.a >= 1.0); + + // If the overall tile cache is known opaque, subpixel AA is allowed everywhere + if has_opaque_bg_color { + return SubpixelMode::Allow; + } + + // If we didn't find any valid opaque backdrop, no subpixel AA allowed + if self.backdrop.opaque_rect.is_empty() { + return SubpixelMode::Deny; + } + + // If the opaque backdrop rect covers the entire tile cache surface, + // we can allow subpixel AA anywhere, skipping the per-text-run tests + // later on during primitive preparation. + if self.backdrop.opaque_rect.contains_box(&self.local_rect) { + return SubpixelMode::Allow; + } + + // If none of the simple cases above match, we need test where we can support subpixel AA. + // TODO(gw): In future, it may make sense to have > 1 inclusion rect, + // but this handles the common cases. + // TODO(gw): If a text run gets animated such that it's moving in a way that is + // sometimes intersecting with the video rect, this can result in subpixel + // AA flicking on/off for that text run. It's probably very rare, but + // something we should handle in future. + SubpixelMode::Conditional { + allowed_rect: self.backdrop.opaque_rect, + } + } + + /// Apply any updates after prim dependency updates. This applies + /// any late tile invalidations, and sets up the dirty rect and + /// set of tile blits. + pub fn post_update( + &mut self, + frame_context: &FrameVisibilityContext, + frame_state: &mut FrameVisibilityState, + ) { + assert!(self.current_surface_traversal_depth == 0); + + self.dirty_region.reset(self.spatial_node_index); + self.subpixel_mode = self.calculate_subpixel_mode(); + + self.transform_index = frame_state.composite_state.register_transform( + self.local_to_surface, + // TODO(gw): Once we support scaling of picture cache tiles during compositing, + // that transform gets plugged in here! + self.surface_to_device, + ); + + let map_pic_to_world = SpaceMapper::new_with_target( + frame_context.root_spatial_node_index, + self.spatial_node_index, + frame_context.global_screen_world_rect, + frame_context.spatial_tree, + ); + + // A simple GC of the native external surface cache, to remove and free any + // surfaces that were not referenced during the update_prim_dependencies pass. + self.external_native_surface_cache.retain(|_, surface| { + if !surface.used_this_frame { + // If we removed an external surface, we need to mark the dirty rects as + // invalid so a full composite occurs on the next frame. + frame_state.composite_state.dirty_rects_are_valid = false; + + frame_state.resource_cache.destroy_compositor_surface(surface.native_surface_id); + } + + surface.used_this_frame + }); + + let pic_to_world_mapper = SpaceMapper::new_with_target( + frame_context.root_spatial_node_index, + self.spatial_node_index, + frame_context.global_screen_world_rect, + frame_context.spatial_tree, + ); + + let ctx = TileUpdateDirtyContext { + pic_to_world_mapper, + global_device_pixel_scale: frame_context.global_device_pixel_scale, + opacity_bindings: &self.opacity_bindings, + color_bindings: &self.color_bindings, + local_rect: self.local_rect, + invalidate_all: self.invalidate_all_tiles, + }; + + let mut state = TileUpdateDirtyState { + resource_cache: frame_state.resource_cache, + composite_state: frame_state.composite_state, + compare_cache: &mut self.compare_cache, + spatial_node_comparer: &mut self.spatial_node_comparer, + }; + + // Step through each tile and invalidate if the dependencies have changed. Determine + // the current opacity setting and whether it's changed. + for sub_slice in &mut self.sub_slices { + for tile in sub_slice.tiles.values_mut() { + tile.update_dirty_and_valid_rects(&ctx, &mut state, frame_context); + } + } + + // Process any deferred dirty checks + for sub_slice in &mut self.sub_slices { + for dirty_test in self.deferred_dirty_tests.drain(..) { + // Calculate the total dirty rect from all tiles that this primitive affects + let mut total_dirty_rect = PictureRect::zero(); + + for y in dirty_test.tile_rect.min.y .. dirty_test.tile_rect.max.y { + for x in dirty_test.tile_rect.min.x .. dirty_test.tile_rect.max.x { + let key = TileOffset::new(x, y); + let tile = sub_slice.tiles.get_mut(&key).expect("bug: no tile"); + total_dirty_rect = total_dirty_rect.union(&tile.local_dirty_rect); + } + } + + // If that dirty rect intersects with the local rect of the primitive + // being checked, invalidate that region in all of the affected tiles. + // TODO(gw): This is somewhat conservative, we could be more clever + // here and avoid invalidating every tile when this changes. + // We could also store the dirty rect only when the prim + // is encountered, so that we don't invalidate if something + // *after* the query in the rendering order affects invalidation. + if total_dirty_rect.intersects(&dirty_test.prim_rect) { + for y in dirty_test.tile_rect.min.y .. dirty_test.tile_rect.max.y { + for x in dirty_test.tile_rect.min.x .. dirty_test.tile_rect.max.x { + let key = TileOffset::new(x, y); + let tile = sub_slice.tiles.get_mut(&key).expect("bug: no tile"); + tile.invalidate( + Some(dirty_test.prim_rect), + InvalidationReason::SurfaceContentChanged, + ); + } + } + } + } + } + + let mut ctx = TilePostUpdateContext { + local_clip_rect: self.local_clip_rect, + backdrop: None, + current_tile_size: self.current_tile_size, + z_id: ZBufferId::invalid(), + }; + + let mut state = TilePostUpdateState { + resource_cache: frame_state.resource_cache, + composite_state: frame_state.composite_state, + }; + + for (i, sub_slice) in self.sub_slices.iter_mut().enumerate().rev() { + // The backdrop is only relevant for the first sub-slice + if i == 0 { + ctx.backdrop = Some(self.backdrop); + } + + for compositor_surface in sub_slice.compositor_surfaces.iter_mut().rev() { + compositor_surface.descriptor.z_id = state.composite_state.z_generator.next(); + } + + ctx.z_id = state.composite_state.z_generator.next(); + + for tile in sub_slice.tiles.values_mut() { + tile.post_update(&ctx, &mut state, frame_context); + } + } + + // Register any opaque external compositor surfaces as potential occluders. This + // is especially useful when viewing video in full-screen mode, as it is + // able to occlude every background tile (avoiding allocation, rasterizion + // and compositing). + + for sub_slice in &self.sub_slices { + for compositor_surface in &sub_slice.compositor_surfaces { + if compositor_surface.is_opaque { + let local_surface_rect = compositor_surface + .descriptor + .local_rect + .intersection(&compositor_surface.descriptor.local_clip_rect) + .and_then(|r| { + r.intersection(&self.local_clip_rect) + }); + + if let Some(local_surface_rect) = local_surface_rect { + let world_surface_rect = map_pic_to_world + .map(&local_surface_rect) + .expect("bug: unable to map external surface to world space"); + + frame_state.composite_state.register_occluder( + compositor_surface.descriptor.z_id, + world_surface_rect, + ); + } + } + } + } + + // Register the opaque region of this tile cache as an occluder, which + // is used later in the frame to occlude other tiles. + if !self.backdrop.opaque_rect.is_empty() { + let z_id_backdrop = frame_state.composite_state.z_generator.next(); + + let backdrop_rect = self.backdrop.opaque_rect + .intersection(&self.local_rect) + .and_then(|r| { + r.intersection(&self.local_clip_rect) + }); + + if let Some(backdrop_rect) = backdrop_rect { + let world_backdrop_rect = map_pic_to_world + .map(&backdrop_rect) + .expect("bug: unable to map backdrop to world space"); + + // Since we register the entire backdrop rect, use the opaque z-id for the + // picture cache slice. + frame_state.composite_state.register_occluder( + z_id_backdrop, + world_backdrop_rect, + ); + } + } + } +} + +pub struct PictureScratchBuffer { + surface_stack: Vec<SurfaceIndex>, +} + +impl Default for PictureScratchBuffer { + fn default() -> Self { + PictureScratchBuffer { + surface_stack: Vec::new(), + } + } +} + +impl PictureScratchBuffer { + pub fn begin_frame(&mut self) { + self.surface_stack.clear(); + } + + pub fn recycle(&mut self, recycler: &mut Recycler) { + recycler.recycle_vec(&mut self.surface_stack); + } +} + +#[derive(Debug, Copy, Clone, PartialEq)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub struct SurfaceIndex(pub usize); + +/// Information about an offscreen surface. For now, +/// it contains information about the size and coordinate +/// system of the surface. In the future, it will contain +/// information about the contents of the surface, which +/// will allow surfaces to be cached / retained between +/// frames and display lists. +pub struct SurfaceInfo { + /// A local rect defining the size of this surface, in the + /// coordinate system of the surface itself. This contains + /// the unclipped bounding rect of child primitives. + pub unclipped_local_rect: PictureRect, + /// The local space coverage of child primitives after they are + /// are clipped to their owning clip-chain. + pub clipped_local_rect: PictureRect, + /// If true, we know this surface is completely opaque + pub is_opaque: bool, + /// The (conservative) valid part of this surface rect. Used + /// to reduce the size of render target allocation. + pub clipping_rect: PictureRect, + /// Helper structs for mapping local rects in different + /// coordinate systems into the surface coordinates. + pub map_local_to_surface: SpaceMapper<LayoutPixel, PicturePixel>, + /// Defines the positioning node for the surface itself, + /// and the rasterization root for this surface. + pub raster_spatial_node_index: SpatialNodeIndex, + pub surface_spatial_node_index: SpatialNodeIndex, + /// The device pixel ratio specific to this surface. + pub device_pixel_scale: DevicePixelScale, + /// The scale factors of the surface to world transform. + pub world_scale_factors: (f32, f32), + /// Local scale factors surface to raster transform + pub local_scale: (f32, f32), + /// If true, allow snapping on this and child surfaces + pub allow_snapping: bool, +} + +impl SurfaceInfo { + pub fn new( + surface_spatial_node_index: SpatialNodeIndex, + raster_spatial_node_index: SpatialNodeIndex, + world_rect: WorldRect, + spatial_tree: &SpatialTree, + device_pixel_scale: DevicePixelScale, + world_scale_factors: (f32, f32), + local_scale: (f32, f32), + allow_snapping: bool, + ) -> Self { + let map_surface_to_world = SpaceMapper::new_with_target( + spatial_tree.root_reference_frame_index(), + surface_spatial_node_index, + world_rect, + spatial_tree, + ); + + let pic_bounds = map_surface_to_world + .unmap(&map_surface_to_world.bounds) + .unwrap_or_else(PictureRect::max_rect); + + let map_local_to_surface = SpaceMapper::new( + surface_spatial_node_index, + pic_bounds, + ); + + SurfaceInfo { + unclipped_local_rect: PictureRect::zero(), + clipped_local_rect: PictureRect::zero(), + is_opaque: false, + clipping_rect: PictureRect::zero(), + map_local_to_surface, + raster_spatial_node_index, + surface_spatial_node_index, + device_pixel_scale, + world_scale_factors, + local_scale, + allow_snapping, + } + } + + /// Clamps the blur radius depending on scale factors. + pub fn clamp_blur_radius( + &self, + x_blur_radius: f32, + y_blur_radius: f32, + ) -> (f32, f32) { + // Clamping must occur after scale factors are applied, but scale factors are not applied + // until later on. To clamp the blur radius, we first apply the scale factors and then clamp + // and finally revert the scale factors. + + let sx_blur_radius = x_blur_radius * self.local_scale.0; + let sy_blur_radius = y_blur_radius * self.local_scale.1; + + let largest_scaled_blur_radius = f32::max( + sx_blur_radius * self.world_scale_factors.0, + sy_blur_radius * self.world_scale_factors.1, + ); + + if largest_scaled_blur_radius > MAX_BLUR_RADIUS { + let sf = MAX_BLUR_RADIUS / largest_scaled_blur_radius; + (x_blur_radius * sf, y_blur_radius * sf) + } else { + // Return the original blur radius to avoid any rounding errors + (x_blur_radius, y_blur_radius) + } + } + + pub fn map_to_device_rect( + &self, + local_rect: &PictureRect, + spatial_tree: &SpatialTree, + ) -> DeviceRect { + let raster_rect = if self.raster_spatial_node_index != self.surface_spatial_node_index { + assert_eq!(self.device_pixel_scale.0, 1.0); + + let local_to_world = SpaceMapper::new_with_target( + spatial_tree.root_reference_frame_index(), + self.surface_spatial_node_index, + WorldRect::max_rect(), + spatial_tree, + ); + + local_to_world.map(&local_rect).unwrap() + } else { + local_rect.cast_unit() + }; + + raster_rect * self.device_pixel_scale + } + + /// Clip and transform a local rect to a device rect suitable for allocating + /// a child off-screen surface of this surface (e.g. for clip-masks) + pub fn get_surface_rect( + &self, + local_rect: &PictureRect, + spatial_tree: &SpatialTree, + ) -> Option<DeviceRect> { + let local_rect = match local_rect.intersection(&self.clipping_rect) { + Some(rect) => rect, + None => return None, + }; + + let raster_rect = if self.raster_spatial_node_index != self.surface_spatial_node_index { + assert_eq!(self.device_pixel_scale.0, 1.0); + + let local_to_world = SpaceMapper::new_with_target( + spatial_tree.root_reference_frame_index(), + self.surface_spatial_node_index, + WorldRect::max_rect(), + spatial_tree, + ); + + local_to_world.map(&local_rect).unwrap() + } else { + local_rect.cast_unit() + }; + + Some((raster_rect * self.device_pixel_scale).round_out()) + } +} + +/// Information from `get_surface_rects` about the allocated size, UV sampling +/// parameters etc for an off-screen surface +struct SurfaceAllocInfo { + task_size: DeviceIntSize, + needs_scissor_rect: bool, + clipped: DeviceRect, + unclipped: DeviceRect, + clipped_local: PictureRect, + uv_rect_kind: UvRectKind, +} + +#[derive(Debug)] +#[cfg_attr(feature = "capture", derive(Serialize))] +pub struct RasterConfig { + /// How this picture should be composited into + /// the parent surface. + // TODO(gw): We should remove this and just use what is in PicturePrimitive + pub composite_mode: PictureCompositeMode, + /// Index to the surface descriptor for this + /// picture. + pub surface_index: SurfaceIndex, +} + +bitflags! { + /// A set of flags describing why a picture may need a backing surface. + #[cfg_attr(feature = "capture", derive(Serialize))] + pub struct BlitReason: u32 { + /// Mix-blend-mode on a child that requires isolation. + const ISOLATE = 1; + /// Clip node that _might_ require a surface. + const CLIP = 2; + /// Preserve-3D requires a surface for plane-splitting. + const PRESERVE3D = 4; + /// A backdrop that is reused which requires a surface. + const BACKDROP = 8; + } +} + +/// Specifies how this Picture should be composited +/// onto the target it belongs to. +#[allow(dead_code)] +#[derive(Debug, Clone)] +#[cfg_attr(feature = "capture", derive(Serialize))] +pub enum PictureCompositeMode { + /// Apply CSS mix-blend-mode effect. + MixBlend(MixBlendMode), + /// Apply a CSS filter (except component transfer). + Filter(Filter), + /// Apply a component transfer filter. + ComponentTransferFilter(FilterDataHandle), + /// Draw to intermediate surface, copy straight across. This + /// is used for CSS isolation, and plane splitting. + Blit(BlitReason), + /// Used to cache a picture as a series of tiles. + TileCache { + slice_id: SliceId, + }, + /// Apply an SVG filter + SvgFilter(Vec<FilterPrimitive>, Vec<SFilterData>), + /// A surface that is used as an input to another primitive + IntermediateSurface, +} + +impl PictureCompositeMode { + pub fn get_rect( + &self, + surface: &SurfaceInfo, + sub_rect: Option<LayoutRect>, + ) -> LayoutRect { + let surface_rect = match sub_rect { + Some(sub_rect) => sub_rect, + None => surface.clipped_local_rect.cast_unit(), + }; + + match self { + PictureCompositeMode::Filter(Filter::Blur { width, height, should_inflate }) => { + if *should_inflate { + let (width_factor, height_factor) = surface.clamp_blur_radius(*width, *height); + + surface_rect.inflate( + width_factor.ceil() * BLUR_SAMPLE_SCALE, + height_factor.ceil() * BLUR_SAMPLE_SCALE, + ) + } else { + surface_rect + } + } + PictureCompositeMode::Filter(Filter::DropShadows(ref shadows)) => { + let mut max_blur_radius = 0.0; + for shadow in shadows { + max_blur_radius = f32::max(max_blur_radius, shadow.blur_radius); + } + + let (max_blur_radius_x, max_blur_radius_y) = surface.clamp_blur_radius( + max_blur_radius, + max_blur_radius, + ); + let blur_inflation_x = max_blur_radius_x * BLUR_SAMPLE_SCALE; + let blur_inflation_y = max_blur_radius_y * BLUR_SAMPLE_SCALE; + + surface_rect.inflate(blur_inflation_x, blur_inflation_y) + } + PictureCompositeMode::SvgFilter(primitives, _) => { + let mut result_rect = surface_rect; + let mut output_rects = Vec::with_capacity(primitives.len()); + + for (cur_index, primitive) in primitives.iter().enumerate() { + let output_rect = match primitive.kind { + FilterPrimitiveKind::Blur(ref primitive) => { + let input = primitive.input.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect); + let width_factor = primitive.width.round() * BLUR_SAMPLE_SCALE; + let height_factor = primitive.height.round() * BLUR_SAMPLE_SCALE; + input.inflate(width_factor, height_factor) + } + FilterPrimitiveKind::DropShadow(ref primitive) => { + let inflation_factor = primitive.shadow.blur_radius.ceil() * BLUR_SAMPLE_SCALE; + let input = primitive.input.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect); + let shadow_rect = input.inflate(inflation_factor, inflation_factor); + input.union(&shadow_rect.translate(primitive.shadow.offset * Scale::new(1.0))) + } + FilterPrimitiveKind::Blend(ref primitive) => { + primitive.input1.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect) + .union(&primitive.input2.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect)) + } + FilterPrimitiveKind::Composite(ref primitive) => { + primitive.input1.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect) + .union(&primitive.input2.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect)) + } + FilterPrimitiveKind::Identity(ref primitive) => + primitive.input.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect), + FilterPrimitiveKind::Opacity(ref primitive) => + primitive.input.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect), + FilterPrimitiveKind::ColorMatrix(ref primitive) => + primitive.input.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect), + FilterPrimitiveKind::ComponentTransfer(ref primitive) => + primitive.input.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect), + FilterPrimitiveKind::Offset(ref primitive) => { + let input_rect = primitive.input.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect); + input_rect.translate(primitive.offset * Scale::new(1.0)) + }, + + FilterPrimitiveKind::Flood(..) => surface_rect, + }; + output_rects.push(output_rect); + result_rect = result_rect.union(&output_rect); + } + result_rect + } + _ => { + surface_rect + } + } + } + + pub fn get_coverage( + &self, + surface: &SurfaceInfo, + sub_rect: Option<LayoutRect>, + ) -> LayoutRect { + let surface_rect = match sub_rect { + Some(sub_rect) => sub_rect, + None => surface.clipped_local_rect.cast_unit(), + }; + + match self { + PictureCompositeMode::Filter(Filter::Blur { width, height, should_inflate }) => { + if *should_inflate { + let (width_factor, height_factor) = surface.clamp_blur_radius(*width, *height); + + surface_rect.inflate( + width_factor.ceil() * BLUR_SAMPLE_SCALE, + height_factor.ceil() * BLUR_SAMPLE_SCALE, + ) + } else { + surface_rect + } + } + PictureCompositeMode::Filter(Filter::DropShadows(ref shadows)) => { + let mut rect = surface_rect; + + for shadow in shadows { + let (blur_radius_x, blur_radius_y) = surface.clamp_blur_radius( + shadow.blur_radius, + shadow.blur_radius, + ); + let blur_inflation_x = blur_radius_x * BLUR_SAMPLE_SCALE; + let blur_inflation_y = blur_radius_y * BLUR_SAMPLE_SCALE; + + let shadow_rect = surface_rect + .translate(shadow.offset) + .inflate(blur_inflation_x, blur_inflation_y); + rect = rect.union(&shadow_rect); + } + + rect + } + PictureCompositeMode::SvgFilter(primitives, _) => { + let mut result_rect = surface_rect; + let mut output_rects = Vec::with_capacity(primitives.len()); + + for (cur_index, primitive) in primitives.iter().enumerate() { + let output_rect = match primitive.kind { + FilterPrimitiveKind::Blur(ref primitive) => { + let input = primitive.input.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect); + let width_factor = primitive.width.round() * BLUR_SAMPLE_SCALE; + let height_factor = primitive.height.round() * BLUR_SAMPLE_SCALE; + + input.inflate(width_factor, height_factor) + } + FilterPrimitiveKind::DropShadow(ref primitive) => { + let inflation_factor = primitive.shadow.blur_radius.ceil() * BLUR_SAMPLE_SCALE; + let input = primitive.input.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect); + let shadow_rect = input.inflate(inflation_factor, inflation_factor); + input.union(&shadow_rect.translate(primitive.shadow.offset * Scale::new(1.0))) + } + FilterPrimitiveKind::Blend(ref primitive) => { + primitive.input1.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect) + .union(&primitive.input2.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect)) + } + FilterPrimitiveKind::Composite(ref primitive) => { + primitive.input1.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect) + .union(&primitive.input2.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect)) + } + FilterPrimitiveKind::Identity(ref primitive) => + primitive.input.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect), + FilterPrimitiveKind::Opacity(ref primitive) => + primitive.input.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect), + FilterPrimitiveKind::ColorMatrix(ref primitive) => + primitive.input.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect), + FilterPrimitiveKind::ComponentTransfer(ref primitive) => + primitive.input.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect), + FilterPrimitiveKind::Offset(ref primitive) => { + let input_rect = primitive.input.to_index(cur_index).map(|index| output_rects[index]).unwrap_or(surface_rect); + input_rect.translate(primitive.offset * Scale::new(1.0)) + }, + + FilterPrimitiveKind::Flood(..) => surface_rect, + }; + output_rects.push(output_rect); + result_rect = result_rect.union(&output_rect); + } + result_rect + } + _ => { + surface_rect + } + } + } +} + +/// Enum value describing the place of a picture in a 3D context. +#[derive(Clone, Debug)] +#[cfg_attr(feature = "capture", derive(Serialize))] +pub enum Picture3DContext<C> { + /// The picture is not a part of 3D context sub-hierarchy. + Out, + /// The picture is a part of 3D context. + In { + /// Additional data per child for the case of this a root of 3D hierarchy. + root_data: Option<Vec<C>>, + /// The spatial node index of an "ancestor" element, i.e. one + /// that establishes the transformed element's containing block. + /// + /// See CSS spec draft for more details: + /// https://drafts.csswg.org/css-transforms-2/#accumulated-3d-transformation-matrix-computation + ancestor_index: SpatialNodeIndex, + /// Index in the built scene's array of plane splitters. + plane_splitter_index: PlaneSplitterIndex, + }, +} + +/// Information about a preserve-3D hierarchy child that has been plane-split +/// and ordered according to the view direction. +#[derive(Clone, Debug)] +#[cfg_attr(feature = "capture", derive(Serialize))] +pub struct OrderedPictureChild { + pub anchor: PlaneSplitAnchor, + pub gpu_address: GpuCacheAddress, +} + +bitflags! { + /// A set of flags describing why a picture may need a backing surface. + #[cfg_attr(feature = "capture", derive(Serialize))] + pub struct ClusterFlags: u32 { + /// Whether this cluster is visible when the position node is a backface. + const IS_BACKFACE_VISIBLE = 1; + /// This flag is set during the first pass picture traversal, depending on whether + /// the cluster is visible or not. It's read during the second pass when primitives + /// consult their owning clusters to see if the primitive itself is visible. + const IS_VISIBLE = 2; + } +} + +/// Descriptor for a cluster of primitives. For now, this is quite basic but will be +/// extended to handle more spatial clustering of primitives. +#[cfg_attr(feature = "capture", derive(Serialize))] +pub struct PrimitiveCluster { + /// The positioning node for this cluster. + pub spatial_node_index: SpatialNodeIndex, + /// The bounding rect of the cluster, in the local space of the spatial node. + /// This is used to quickly determine the overall bounding rect for a picture + /// during the first picture traversal, which is needed for local scale + /// determination, and render task size calculations. + bounding_rect: LayoutRect, + /// a part of the cluster that we know to be opaque if any. Does not always + /// describe the entire opaque region, but all content within that rect must + /// be opaque. + pub opaque_rect: LayoutRect, + /// The range of primitive instance indices associated with this cluster. + pub prim_range: Range<usize>, + /// Various flags / state for this cluster. + pub flags: ClusterFlags, +} + +impl PrimitiveCluster { + /// Construct a new primitive cluster for a given positioning node. + fn new( + spatial_node_index: SpatialNodeIndex, + flags: ClusterFlags, + first_instance_index: usize, + ) -> Self { + PrimitiveCluster { + bounding_rect: LayoutRect::zero(), + opaque_rect: LayoutRect::zero(), + spatial_node_index, + flags, + prim_range: first_instance_index..first_instance_index + } + } + + /// Return true if this cluster is compatible with the given params + pub fn is_compatible( + &self, + spatial_node_index: SpatialNodeIndex, + flags: ClusterFlags, + instance_index: usize, + ) -> bool { + self.flags == flags && + self.spatial_node_index == spatial_node_index && + instance_index == self.prim_range.end + } + + pub fn prim_range(&self) -> Range<usize> { + self.prim_range.clone() + } + + /// Add a primitive instance to this cluster, at the start or end + fn add_instance( + &mut self, + culling_rect: &LayoutRect, + instance_index: usize, + ) { + debug_assert_eq!(instance_index, self.prim_range.end); + self.bounding_rect = self.bounding_rect.union(culling_rect); + self.prim_range.end += 1; + } +} + +/// A list of primitive instances that are added to a picture +/// This ensures we can keep a list of primitives that +/// are pictures, for a fast initial traversal of the picture +/// tree without walking the instance list. +#[cfg_attr(feature = "capture", derive(Serialize))] +pub struct PrimitiveList { + /// List of primitives grouped into clusters. + pub clusters: Vec<PrimitiveCluster>, + pub child_pictures: Vec<PictureIndex>, + /// The number of preferred compositor surfaces that were found when + /// adding prims to this list. + pub compositor_surface_count: usize, +} + +impl PrimitiveList { + /// Construct an empty primitive list. This is + /// just used during the take_context / restore_context + /// borrow check dance, which will be removed as the + /// picture traversal pass is completed. + pub fn empty() -> Self { + PrimitiveList { + clusters: Vec::new(), + child_pictures: Vec::new(), + compositor_surface_count: 0, + } + } + + pub fn merge(&mut self, other: PrimitiveList) { + self.clusters.extend(other.clusters); + self.child_pictures.extend(other.child_pictures); + self.compositor_surface_count += other.compositor_surface_count; + } + + /// Add a primitive instance to the end of the list + pub fn add_prim( + &mut self, + prim_instance: PrimitiveInstance, + prim_rect: LayoutRect, + spatial_node_index: SpatialNodeIndex, + prim_flags: PrimitiveFlags, + prim_instances: &mut Vec<PrimitiveInstance>, + clip_tree_builder: &ClipTreeBuilder, + ) { + let mut flags = ClusterFlags::empty(); + + // Pictures are always put into a new cluster, to make it faster to + // iterate all pictures in a given primitive list. + match prim_instance.kind { + PrimitiveInstanceKind::Picture { pic_index, .. } => { + self.child_pictures.push(pic_index); + } + _ => {} + } + + if prim_flags.contains(PrimitiveFlags::IS_BACKFACE_VISIBLE) { + flags.insert(ClusterFlags::IS_BACKFACE_VISIBLE); + } + + if prim_flags.contains(PrimitiveFlags::PREFER_COMPOSITOR_SURFACE) { + self.compositor_surface_count += 1; + } + + let clip_leaf = clip_tree_builder.get_leaf(prim_instance.clip_leaf_id); + let culling_rect = clip_leaf.local_clip_rect + .intersection(&prim_rect) + .unwrap_or_else(LayoutRect::zero); + + let instance_index = prim_instances.len(); + prim_instances.push(prim_instance); + + if let Some(cluster) = self.clusters.last_mut() { + if cluster.is_compatible(spatial_node_index, flags, instance_index) { + cluster.add_instance(&culling_rect, instance_index); + return; + } + } + + // Same idea with clusters, using a different distribution. + let clusters_len = self.clusters.len(); + if clusters_len == self.clusters.capacity() { + let next_alloc = match clusters_len { + 1 ..= 15 => 16 - clusters_len, + 16 ..= 127 => 128 - clusters_len, + _ => clusters_len * 2, + }; + + self.clusters.reserve(next_alloc); + } + + let mut cluster = PrimitiveCluster::new( + spatial_node_index, + flags, + instance_index, + ); + + cluster.add_instance(&culling_rect, instance_index); + self.clusters.push(cluster); + } + + /// Returns true if there are no clusters (and thus primitives) + pub fn is_empty(&self) -> bool { + self.clusters.is_empty() + } +} + +bitflags! { + #[cfg_attr(feature = "capture", derive(Serialize))] + /// Flags describing properties for a given PicturePrimitive + pub struct PictureFlags : u8 { + /// This picture is a resolve target (doesn't actually render content itself, + /// will have content copied in to it) + const IS_RESOLVE_TARGET = 1 << 0; + /// This picture establishes a sub-graph, which affects how SurfaceBuilder will + /// set up dependencies in the render task graph + const IS_SUB_GRAPH = 1 << 1; + /// If set, this picture should not apply snapping via changing the raster root + const DISABLE_SNAPPING = 1 << 2; + } +} + +#[cfg_attr(feature = "capture", derive(Serialize))] +pub struct PicturePrimitive { + /// List of primitives, and associated info for this picture. + pub prim_list: PrimitiveList, + + /// If false and transform ends up showing the back of the picture, + /// it will be considered invisible. + pub is_backface_visible: bool, + + pub primary_render_task_id: Option<RenderTaskId>, + /// If a mix-blend-mode, contains the render task for + /// the readback of the framebuffer that we use to sample + /// from in the mix-blend-mode shader. + /// For drop-shadow filter, this will store the original + /// picture task which would be rendered on screen after + /// blur pass. + pub secondary_render_task_id: Option<RenderTaskId>, + /// How this picture should be composited. + /// If None, don't composite - just draw directly on parent surface. + pub composite_mode: Option<PictureCompositeMode>, + + pub raster_config: Option<RasterConfig>, + pub context_3d: Picture3DContext<OrderedPictureChild>, + + // Optional cache handles for storing extra data + // in the GPU cache, depending on the type of + // picture. + pub extra_gpu_data_handles: SmallVec<[GpuCacheHandle; 1]>, + + /// The spatial node index of this picture when it is + /// composited into the parent picture. + pub spatial_node_index: SpatialNodeIndex, + + /// Store the state of the previous local rect + /// for this picture. We need this in order to know when + /// to invalidate segments / drop-shadow gpu cache handles. + pub prev_local_rect: LayoutRect, + + /// If false, this picture needs to (re)build segments + /// if it supports segment rendering. This can occur + /// if the local rect of the picture changes due to + /// transform animation and/or scrolling. + pub segments_are_valid: bool, + + /// Set to true if we know for sure the picture is fully opaque. + pub is_opaque: bool, + + /// Requested raster space for this picture + pub raster_space: RasterSpace, + + /// Flags for this picture primitive + pub flags: PictureFlags, +} + +impl PicturePrimitive { + pub fn print<T: PrintTreePrinter>( + &self, + pictures: &[Self], + self_index: PictureIndex, + pt: &mut T, + ) { + pt.new_level(format!("{:?}", self_index)); + pt.add_item(format!("cluster_count: {:?}", self.prim_list.clusters.len())); + pt.add_item(format!("spatial_node_index: {:?}", self.spatial_node_index)); + pt.add_item(format!("raster_config: {:?}", self.raster_config)); + pt.add_item(format!("composite_mode: {:?}", self.composite_mode)); + pt.add_item(format!("flags: {:?}", self.flags)); + + for child_pic_index in &self.prim_list.child_pictures { + pictures[child_pic_index.0].print(pictures, *child_pic_index, pt); + } + + pt.end_level(); + } + + /// Returns true if this picture supports segmented rendering. + pub fn can_use_segments(&self) -> bool { + match self.raster_config { + // TODO(gw): Support brush segment rendering for filter and mix-blend + // shaders. It's possible this already works, but I'm just + // applying this optimization to Blit mode for now. + Some(RasterConfig { composite_mode: PictureCompositeMode::MixBlend(..), .. }) | + Some(RasterConfig { composite_mode: PictureCompositeMode::Filter(..), .. }) | + Some(RasterConfig { composite_mode: PictureCompositeMode::ComponentTransferFilter(..), .. }) | + Some(RasterConfig { composite_mode: PictureCompositeMode::TileCache { .. }, .. }) | + Some(RasterConfig { composite_mode: PictureCompositeMode::SvgFilter(..), .. }) | + Some(RasterConfig { composite_mode: PictureCompositeMode::IntermediateSurface, .. }) | + None => { + false + } + Some(RasterConfig { composite_mode: PictureCompositeMode::Blit(reason), ..}) => { + reason == BlitReason::CLIP + } + } + } + + fn resolve_scene_properties(&mut self, properties: &SceneProperties) { + match self.composite_mode { + Some(PictureCompositeMode::Filter(ref mut filter)) => { + match *filter { + Filter::Opacity(ref binding, ref mut value) => { + *value = properties.resolve_float(binding); + } + _ => {} + } + } + _ => {} + } + } + + pub fn is_visible( + &self, + spatial_tree: &SpatialTree, + ) -> bool { + if let Some(PictureCompositeMode::Filter(ref filter)) = self.composite_mode { + if !filter.is_visible() { + return false; + } + } + + // For out-of-preserve-3d pictures, the backface visibility is determined by + // the local transform only. + // Note: we aren't taking the transform relative to the parent picture, + // since picture tree can be more dense than the corresponding spatial tree. + if !self.is_backface_visible { + if let Picture3DContext::Out = self.context_3d { + match spatial_tree.get_local_visible_face(self.spatial_node_index) { + VisibleFace::Front => {} + VisibleFace::Back => return false, + } + } + } + + true + } + + pub fn new_image( + composite_mode: Option<PictureCompositeMode>, + context_3d: Picture3DContext<OrderedPictureChild>, + prim_flags: PrimitiveFlags, + prim_list: PrimitiveList, + spatial_node_index: SpatialNodeIndex, + raster_space: RasterSpace, + flags: PictureFlags, + ) -> Self { + PicturePrimitive { + prim_list, + primary_render_task_id: None, + secondary_render_task_id: None, + composite_mode, + raster_config: None, + context_3d, + extra_gpu_data_handles: SmallVec::new(), + is_backface_visible: prim_flags.contains(PrimitiveFlags::IS_BACKFACE_VISIBLE), + spatial_node_index, + prev_local_rect: LayoutRect::zero(), + segments_are_valid: false, + is_opaque: false, + raster_space, + flags, + } + } + + pub fn take_context( + &mut self, + pic_index: PictureIndex, + parent_surface_index: Option<SurfaceIndex>, + parent_subpixel_mode: SubpixelMode, + frame_state: &mut FrameBuildingState, + frame_context: &FrameBuildingContext, + scratch: &mut PrimitiveScratchBuffer, + tile_caches: &mut FastHashMap<SliceId, Box<TileCacheInstance>>, + ) -> Option<(PictureContext, PictureState, PrimitiveList)> { + self.primary_render_task_id = None; + self.secondary_render_task_id = None; + + if !self.is_visible(frame_context.spatial_tree) { + return None; + } + + profile_scope!("take_context"); + + let surface_index = match self.raster_config { + Some(ref raster_config) => raster_config.surface_index, + None => parent_surface_index.expect("bug: no parent"), + }; + let surface_spatial_node_index = frame_state.surfaces[surface_index.0].surface_spatial_node_index; + + let map_pic_to_world = SpaceMapper::new_with_target( + frame_context.root_spatial_node_index, + surface_spatial_node_index, + frame_context.global_screen_world_rect, + frame_context.spatial_tree, + ); + + let pic_bounds = map_pic_to_world + .unmap(&map_pic_to_world.bounds) + .unwrap_or_else(PictureRect::max_rect); + + let map_local_to_pic = SpaceMapper::new( + surface_spatial_node_index, + pic_bounds, + ); + + match self.raster_config { + Some(RasterConfig { surface_index, composite_mode: PictureCompositeMode::TileCache { slice_id }, .. }) => { + let tile_cache = tile_caches.get_mut(&slice_id).unwrap(); + let mut debug_info = SliceDebugInfo::new(); + let mut surface_render_tasks = FastHashMap::default(); + let mut surface_local_dirty_rect = PictureRect::zero(); + let device_pixel_scale = frame_state + .surfaces[surface_index.0] + .device_pixel_scale; + let mut at_least_one_tile_visible = false; + + // Get the overall world space rect of the picture cache. Used to clip + // the tile rects below for occlusion testing to the relevant area. + let world_clip_rect = map_pic_to_world + .map(&tile_cache.local_clip_rect) + .expect("bug: unable to map clip rect") + .round(); + let device_clip_rect = (world_clip_rect * frame_context.global_device_pixel_scale).round(); + + for (sub_slice_index, sub_slice) in tile_cache.sub_slices.iter_mut().enumerate() { + for tile in sub_slice.tiles.values_mut() { + if tile.is_visible { + // Get the world space rect that this tile will actually occupy on screen + let world_draw_rect = world_clip_rect.intersection(&tile.world_valid_rect); + + // If that draw rect is occluded by some set of tiles in front of it, + // then mark it as not visible and skip drawing. When it's not occluded + // it will fail this test, and get rasterized by the render task setup + // code below. + match world_draw_rect { + Some(world_draw_rect) => { + // Only check for occlusion on visible tiles that are fixed position. + if tile_cache.spatial_node_index == frame_context.root_spatial_node_index && + frame_state.composite_state.occluders.is_tile_occluded(tile.z_id, world_draw_rect) { + // If this tile has an allocated native surface, free it, since it's completely + // occluded. We will need to re-allocate this surface if it becomes visible, + // but that's likely to be rare (e.g. when there is no content display list + // for a frame or two during a tab switch). + let surface = tile.surface.as_mut().expect("no tile surface set!"); + + if let TileSurface::Texture { descriptor: SurfaceTextureDescriptor::Native { id, .. }, .. } = surface { + if let Some(id) = id.take() { + frame_state.resource_cache.destroy_compositor_tile(id); + } + } + + tile.is_visible = false; + + if frame_context.fb_config.testing { + debug_info.tiles.insert( + tile.tile_offset, + TileDebugInfo::Occluded, + ); + } + + continue; + } + } + None => { + tile.is_visible = false; + } + } + } + + // If we get here, we want to ensure that the surface remains valid in the texture + // cache, _even if_ it's not visible due to clipping or being scrolled off-screen. + // This ensures that we retain valid tiles that are off-screen, but still in the + // display port of this tile cache instance. + if let Some(TileSurface::Texture { descriptor, .. }) = tile.surface.as_ref() { + if let SurfaceTextureDescriptor::TextureCache { handle: Some(handle), .. } = descriptor { + frame_state.resource_cache + .picture_textures.request(handle, frame_state.gpu_cache); + } + } + + // If the tile has been found to be off-screen / clipped, skip any further processing. + if !tile.is_visible { + if frame_context.fb_config.testing { + debug_info.tiles.insert( + tile.tile_offset, + TileDebugInfo::Culled, + ); + } + + continue; + } + + at_least_one_tile_visible = true; + + if frame_context.debug_flags.contains(DebugFlags::PICTURE_CACHING_DBG) { + tile.root.draw_debug_rects( + &map_pic_to_world, + tile.is_opaque, + tile.current_descriptor.local_valid_rect, + scratch, + frame_context.global_device_pixel_scale, + ); + + let label_offset = DeviceVector2D::new( + 20.0 + sub_slice_index as f32 * 20.0, + 30.0 + sub_slice_index as f32 * 20.0, + ); + let tile_device_rect = tile.world_tile_rect * frame_context.global_device_pixel_scale; + if tile_device_rect.height() >= label_offset.y { + let surface = tile.surface.as_ref().expect("no tile surface set!"); + + scratch.push_debug_string( + tile_device_rect.min + label_offset, + debug_colors::RED, + format!("{:?}: s={} is_opaque={} surface={} sub={}", + tile.id, + tile_cache.slice, + tile.is_opaque, + surface.kind(), + sub_slice_index, + ), + ); + } + } + + if let TileSurface::Texture { descriptor, .. } = tile.surface.as_mut().unwrap() { + match descriptor { + SurfaceTextureDescriptor::TextureCache { ref handle, .. } => { + let exists = handle.as_ref().map_or(false, + |handle| frame_state.resource_cache.picture_textures.entry_exists(handle) + ); + // Invalidate if the backing texture was evicted. + if exists { + // Request the backing texture so it won't get evicted this frame. + // We specifically want to mark the tile texture as used, even + // if it's detected not visible below and skipped. This is because + // we maintain the set of tiles we care about based on visibility + // during pre_update. If a tile still exists after that, we are + // assuming that it's either visible or we want to retain it for + // a while in case it gets scrolled back onto screen soon. + // TODO(gw): Consider switching to manual eviction policy? + frame_state.resource_cache + .picture_textures + .request(handle.as_ref().unwrap(), frame_state.gpu_cache); + } else { + // If the texture was evicted on a previous frame, we need to assume + // that the entire tile rect is dirty. + tile.invalidate(None, InvalidationReason::NoTexture); + } + } + SurfaceTextureDescriptor::Native { id, .. } => { + if id.is_none() { + // There is no current surface allocation, so ensure the entire tile is invalidated + tile.invalidate(None, InvalidationReason::NoSurface); + } + } + } + } + + // Ensure that the dirty rect doesn't extend outside the local valid rect. + tile.local_dirty_rect = tile.local_dirty_rect + .intersection(&tile.current_descriptor.local_valid_rect) + .unwrap_or_else(PictureRect::zero); + + surface_local_dirty_rect = surface_local_dirty_rect.union(&tile.local_dirty_rect); + + // Update the world/device dirty rect + let world_dirty_rect = map_pic_to_world.map(&tile.local_dirty_rect).expect("bug"); + + let device_rect = (tile.world_tile_rect * frame_context.global_device_pixel_scale).round(); + tile.device_dirty_rect = (world_dirty_rect * frame_context.global_device_pixel_scale) + .round_out() + .intersection(&device_rect) + .unwrap_or_else(DeviceRect::zero); + + if tile.is_valid { + if frame_context.fb_config.testing { + debug_info.tiles.insert( + tile.tile_offset, + TileDebugInfo::Valid, + ); + } + } else { + // Add this dirty rect to the dirty region tracker. This must be done outside the if statement below, + // so that we include in the dirty region tiles that are handled by a background color only (no + // surface allocation). + tile_cache.dirty_region.add_dirty_region( + tile.local_dirty_rect, + frame_context.spatial_tree, + ); + + // Ensure that this texture is allocated. + if let TileSurface::Texture { ref mut descriptor } = tile.surface.as_mut().unwrap() { + match descriptor { + SurfaceTextureDescriptor::TextureCache { ref mut handle } => { + + frame_state.resource_cache.picture_textures.update( + tile_cache.current_tile_size, + handle, + frame_state.gpu_cache, + &mut frame_state.resource_cache.texture_cache.next_id, + &mut frame_state.resource_cache.texture_cache.pending_updates, + ); + } + SurfaceTextureDescriptor::Native { id } => { + if id.is_none() { + // Allocate a native surface id if we're in native compositing mode, + // and we don't have a surface yet (due to first frame, or destruction + // due to tile size changing etc). + if sub_slice.native_surface.is_none() { + let opaque = frame_state + .resource_cache + .create_compositor_surface( + tile_cache.virtual_offset, + tile_cache.current_tile_size, + true, + ); + + let alpha = frame_state + .resource_cache + .create_compositor_surface( + tile_cache.virtual_offset, + tile_cache.current_tile_size, + false, + ); + + sub_slice.native_surface = Some(NativeSurface { + opaque, + alpha, + }); + } + + // Create the tile identifier and allocate it. + let surface_id = if tile.is_opaque { + sub_slice.native_surface.as_ref().unwrap().opaque + } else { + sub_slice.native_surface.as_ref().unwrap().alpha + }; + + let tile_id = NativeTileId { + surface_id, + x: tile.tile_offset.x, + y: tile.tile_offset.y, + }; + + frame_state.resource_cache.create_compositor_tile(tile_id); + + *id = Some(tile_id); + } + } + } + + // The cast_unit() here is because the `content_origin` is expected to be in + // device pixels, however we're establishing raster roots for picture cache + // tiles meaning the `content_origin` needs to be in the local space of that root. + // TODO(gw): `content_origin` should actually be in RasterPixels to be consistent + // with both local / screen raster modes, but this involves a lot of + // changes to render task and picture code. + let content_origin_f = tile.local_tile_rect.min.cast_unit() * device_pixel_scale; + let content_origin = content_origin_f.round(); + // TODO: these asserts used to have a threshold of 0.01 but failed intermittently the + // gfx/layers/apz/test/mochitest/test_group_double_tap_zoom-2.html test on android. + // moving the rectangles in space mapping conversion code to the Box2D representaton + // made the failure happen more often. + debug_assert!((content_origin_f.x - content_origin.x).abs() < 0.15); + debug_assert!((content_origin_f.y - content_origin.y).abs() < 0.15); + + let surface = descriptor.resolve( + frame_state.resource_cache, + tile_cache.current_tile_size, + ); + + let scissor_rect = frame_state.composite_state.get_surface_rect( + &tile.local_dirty_rect, + &tile.local_tile_rect, + tile_cache.transform_index, + ).to_i32(); + + let valid_rect = frame_state.composite_state.get_surface_rect( + &tile.current_descriptor.local_valid_rect, + &tile.local_tile_rect, + tile_cache.transform_index, + ).to_i32(); + + let composite_task_size = tile_cache.current_tile_size; + + let tile_key = TileKey { + sub_slice_index: SubSliceIndex::new(sub_slice_index), + tile_offset: tile.tile_offset, + }; + + let mut clear_color = ColorF::TRANSPARENT; + + if SubSliceIndex::new(sub_slice_index).is_primary() { + if let Some(background_color) = tile_cache.background_color { + clear_color = background_color; + } + + // If this picture cache has a spanning_opaque_color, we will use + // that as the clear color. The primitive that was detected as a + // spanning primitive will have been set with IS_BACKDROP, causing + // it to be skipped and removing everything added prior to it + // during batching. + if let Some(color) = tile_cache.backdrop.spanning_opaque_color { + clear_color = color; + } + } + + let cmd_buffer_index = frame_state.cmd_buffers.create_cmd_buffer(); + + // TODO(gw): As a performance optimization, we could skip the resolve picture + // if the dirty rect is the same as the resolve rect (probably quite + // common for effects that scroll underneath a backdrop-filter, for example). + let use_tile_composite = !tile.sub_graphs.is_empty(); + + if use_tile_composite { + let mut local_content_rect = tile.local_dirty_rect; + + for (sub_graph_rect, surface_stack) in &tile.sub_graphs { + if let Some(dirty_sub_graph_rect) = sub_graph_rect.intersection(&tile.local_dirty_rect) { + for (composite_mode, surface_index) in surface_stack { + let surface = &frame_state.surfaces[surface_index.0]; + + let rect = composite_mode.get_coverage( + surface, + Some(dirty_sub_graph_rect.cast_unit()), + ).cast_unit(); + + local_content_rect = local_content_rect.union(&rect); + } + } + } + + // We know that we'll never need to sample > 300 device pixels outside the tile + // for blurring, so clamp the content rect here so that we don't try to allocate + // a really large surface in the case of a drop-shadow with large offset. + let max_content_rect = (tile.local_dirty_rect.cast_unit() * device_pixel_scale) + .inflate( + MAX_BLUR_RADIUS * BLUR_SAMPLE_SCALE, + MAX_BLUR_RADIUS * BLUR_SAMPLE_SCALE, + ) + .round_out() + .to_i32(); + + let content_device_rect = (local_content_rect.cast_unit() * device_pixel_scale) + .round_out() + .to_i32(); + + let content_device_rect = content_device_rect + .intersection(&max_content_rect) + .expect("bug: no intersection with tile dirty rect"); + + let content_task_size = content_device_rect.size(); + let normalized_content_rect = content_task_size.into(); + + let inner_offset = content_origin + scissor_rect.min.to_vector().to_f32(); + let outer_offset = content_device_rect.min.to_f32(); + let sub_rect_offset = (inner_offset - outer_offset).round().to_i32(); + + let render_task_id = frame_state.rg_builder.add().init( + RenderTask::new_dynamic( + content_task_size, + RenderTaskKind::new_picture( + content_task_size, + true, + content_device_rect.min.to_f32(), + surface_spatial_node_index, + // raster == surface implicitly for picture cache tiles + surface_spatial_node_index, + device_pixel_scale, + Some(normalized_content_rect), + None, + Some(clear_color), + cmd_buffer_index, + false, + ) + ), + ); + + let composite_task_id = frame_state.rg_builder.add().init( + RenderTask::new( + RenderTaskLocation::Static { + surface: StaticRenderTaskSurface::PictureCache { + surface, + }, + rect: composite_task_size.into(), + }, + RenderTaskKind::new_tile_composite( + sub_rect_offset, + scissor_rect, + valid_rect, + clear_color, + ), + ), + ); + + surface_render_tasks.insert( + tile_key, + SurfaceTileDescriptor { + current_task_id: render_task_id, + composite_task_id: Some(composite_task_id), + dirty_rect: tile.local_dirty_rect, + }, + ); + } else { + let render_task_id = frame_state.rg_builder.add().init( + RenderTask::new( + RenderTaskLocation::Static { + surface: StaticRenderTaskSurface::PictureCache { + surface, + }, + rect: composite_task_size.into(), + }, + RenderTaskKind::new_picture( + composite_task_size, + true, + content_origin, + surface_spatial_node_index, + // raster == surface implicitly for picture cache tiles + surface_spatial_node_index, + device_pixel_scale, + Some(scissor_rect), + Some(valid_rect), + Some(clear_color), + cmd_buffer_index, + false, + ) + ), + ); + + surface_render_tasks.insert( + tile_key, + SurfaceTileDescriptor { + current_task_id: render_task_id, + composite_task_id: None, + dirty_rect: tile.local_dirty_rect, + }, + ); + } + } + + if frame_context.fb_config.testing { + debug_info.tiles.insert( + tile.tile_offset, + TileDebugInfo::Dirty(DirtyTileDebugInfo { + local_valid_rect: tile.current_descriptor.local_valid_rect, + local_dirty_rect: tile.local_dirty_rect, + }), + ); + } + } + + let surface = tile.surface.as_ref().expect("no tile surface set!"); + + let descriptor = CompositeTileDescriptor { + surface_kind: surface.into(), + tile_id: tile.id, + }; + + let (surface, is_opaque) = match surface { + TileSurface::Color { color } => { + (CompositeTileSurface::Color { color: *color }, true) + } + TileSurface::Clear => { + // Clear tiles are rendered with blend mode pre-multiply-dest-out. + (CompositeTileSurface::Clear, false) + } + TileSurface::Texture { descriptor, .. } => { + let surface = descriptor.resolve(frame_state.resource_cache, tile_cache.current_tile_size); + ( + CompositeTileSurface::Texture { surface }, + tile.is_opaque + ) + } + }; + + if is_opaque { + sub_slice.opaque_tile_descriptors.push(descriptor); + } else { + sub_slice.alpha_tile_descriptors.push(descriptor); + } + + let composite_tile = CompositeTile { + kind: tile_kind(&surface, is_opaque), + surface, + local_rect: tile.local_tile_rect, + local_valid_rect: tile.current_descriptor.local_valid_rect, + local_dirty_rect: tile.local_dirty_rect, + device_clip_rect, + z_id: tile.z_id, + transform_index: tile_cache.transform_index, + }; + + sub_slice.composite_tiles.push(composite_tile); + + // Now that the tile is valid, reset the dirty rect. + tile.local_dirty_rect = PictureRect::zero(); + tile.is_valid = true; + } + + // Sort the tile descriptor lists, since iterating values in the tile_cache.tiles + // hashmap doesn't provide any ordering guarantees, but we want to detect the + // composite descriptor as equal if the tiles list is the same, regardless of + // ordering. + sub_slice.opaque_tile_descriptors.sort_by_key(|desc| desc.tile_id); + sub_slice.alpha_tile_descriptors.sort_by_key(|desc| desc.tile_id); + } + + // Check to see if we should add backdrops as native surfaces. + let backdrop_rect = tile_cache.backdrop.backdrop_rect + .intersection(&tile_cache.local_rect) + .and_then(|r| { + r.intersection(&tile_cache.local_clip_rect) + }); + + let mut backdrop_in_use_and_visible = false; + if let Some(backdrop_rect) = backdrop_rect { + let supports_surface_for_backdrop = match frame_state.composite_state.compositor_kind { + CompositorKind::Draw { .. } => { + false + } + CompositorKind::Native { capabilities, .. } => { + capabilities.supports_surface_for_backdrop + } + }; + if supports_surface_for_backdrop && !tile_cache.found_prims_after_backdrop && at_least_one_tile_visible { + if let Some(BackdropKind::Color { color }) = tile_cache.backdrop.kind { + backdrop_in_use_and_visible = true; + + // We're going to let the compositor handle the backdrop as a native surface. + // Hide all of our sub_slice tiles so they aren't also trying to draw it. + for sub_slice in &mut tile_cache.sub_slices { + for tile in sub_slice.tiles.values_mut() { + tile.is_visible = false; + } + } + + // Destroy our backdrop surface if it doesn't match the new color. + // TODO: This is a performance hit for animated color backdrops. + if let Some(backdrop_surface) = &tile_cache.backdrop_surface { + if backdrop_surface.color != color { + frame_state.resource_cache.destroy_compositor_surface(backdrop_surface.id); + tile_cache.backdrop_surface = None; + } + } + + // Calculate the device_rect for the backdrop, which is just the backdrop_rect + // converted into world space and scaled to device pixels. + let world_backdrop_rect = map_pic_to_world.map(&backdrop_rect).expect("bug: unable to map backdrop rect"); + let device_rect = (world_backdrop_rect * frame_context.global_device_pixel_scale).round(); + + // If we already have a backdrop surface, update the device rect. Otherwise, create + // a backdrop surface. + if let Some(backdrop_surface) = &mut tile_cache.backdrop_surface { + backdrop_surface.device_rect = device_rect; + } else { + // Create native compositor surface with color for the backdrop and store the id. + tile_cache.backdrop_surface = Some(BackdropSurface { + id: frame_state.resource_cache.create_compositor_backdrop_surface(color), + color, + device_rect, + }); + } + } + } + } + + if !backdrop_in_use_and_visible { + if let Some(backdrop_surface) = &tile_cache.backdrop_surface { + // We've already allocated a backdrop surface, but we're not using it. + // Tell the compositor to get rid of it. + frame_state.resource_cache.destroy_compositor_surface(backdrop_surface.id); + tile_cache.backdrop_surface = None; + } + } + + // If invalidation debugging is enabled, dump the picture cache state to a tree printer. + if frame_context.debug_flags.contains(DebugFlags::INVALIDATION_DBG) { + tile_cache.print(); + } + + // If testing mode is enabled, write some information about the current state + // of this picture cache (made available in RenderResults). + if frame_context.fb_config.testing { + frame_state.composite_state + .picture_cache_debug + .slices + .insert( + tile_cache.slice, + debug_info, + ); + } + + let descriptor = SurfaceDescriptor::new_tiled(surface_render_tasks); + + frame_state.surface_builder.push_surface( + surface_index, + false, + surface_local_dirty_rect, + descriptor, + frame_state.surfaces, + frame_state.rg_builder, + ); + } + Some(ref mut raster_config) => { + let pic_rect = frame_state + .surfaces[raster_config.surface_index.0] + .clipped_local_rect; + + let parent_surface_index = parent_surface_index.expect("bug: no parent for child surface"); + + // Layout space for the picture is picture space from the + // perspective of its child primitives. + let local_rect = pic_rect * Scale::new(1.0); + + // If the precise rect changed since last frame, we need to invalidate + // any segments and gpu cache handles for drop-shadows. + // TODO(gw): Requiring storage of the `prev_precise_local_rect` here + // is a total hack. It's required because `prev_precise_local_rect` + // gets written to twice (during initial vis pass and also during + // prepare pass). The proper longer term fix for this is to make + // use of the conservative picture rect for segmenting (which should + // be done during scene building). + if local_rect != self.prev_local_rect { + match raster_config.composite_mode { + PictureCompositeMode::Filter(Filter::DropShadows(..)) => { + for handle in &self.extra_gpu_data_handles { + frame_state.gpu_cache.invalidate(handle); + } + } + _ => {} + } + // Invalidate any segments built for this picture, since the local + // rect has changed. + self.segments_are_valid = false; + self.prev_local_rect = local_rect; + } + + let max_surface_size = frame_context + .fb_config + .max_surface_override + .unwrap_or(MAX_SURFACE_SIZE) as f32; + + let surface_rects = match get_surface_rects( + raster_config.surface_index, + &raster_config.composite_mode, + parent_surface_index, + &mut frame_state.surfaces, + frame_context.spatial_tree, + max_surface_size, + ) { + Some(rects) => rects, + None => return None, + }; + + let (raster_spatial_node_index, device_pixel_scale) = { + let surface = &frame_state.surfaces[surface_index.0]; + (surface.raster_spatial_node_index, surface.device_pixel_scale) + }; + let can_use_shared_surface = !self.flags.contains(PictureFlags::IS_RESOLVE_TARGET); + + let primary_render_task_id; + let surface_descriptor; + match raster_config.composite_mode { + PictureCompositeMode::TileCache { .. } => { + unreachable!("handled above"); + } + PictureCompositeMode::Filter(Filter::Blur { width, height, .. }) => { + let surface = &frame_state.surfaces[raster_config.surface_index.0]; + let (width, height) = surface.clamp_blur_radius(width, height); + + let width_std_deviation = width * surface.local_scale.0 * device_pixel_scale.0; + let height_std_deviation = height * surface.local_scale.1 * device_pixel_scale.0; + let blur_std_deviation = DeviceSize::new( + width_std_deviation, + height_std_deviation, + ); + + let original_size = surface_rects.clipped.size(); + + // Adjust the size to avoid introducing sampling errors during the down-scaling passes. + // what would be even better is to rasterize the picture at the down-scaled size + // directly. + let adjusted_size = BlurTask::adjusted_blur_source_size( + original_size, + blur_std_deviation, + ); + + let cmd_buffer_index = frame_state.cmd_buffers.create_cmd_buffer(); + + // Since we (may have) adjusted the render task size for downscaling accuracy + // above, recalculate the uv rect for tasks that may sample from this blur output + let uv_rect_kind = calculate_uv_rect_kind( + DeviceRect::from_origin_and_size(surface_rects.clipped.min, adjusted_size.to_f32()), + surface_rects.unclipped, + ); + + let picture_task_id = frame_state.rg_builder.add().init( + RenderTask::new_dynamic( + adjusted_size, + RenderTaskKind::new_picture( + adjusted_size, + surface_rects.needs_scissor_rect, + surface_rects.clipped.min, + surface_spatial_node_index, + raster_spatial_node_index, + device_pixel_scale, + None, + None, + None, + cmd_buffer_index, + can_use_shared_surface, + ) + ).with_uv_rect_kind(uv_rect_kind) + ); + + let blur_render_task_id = RenderTask::new_blur( + blur_std_deviation, + picture_task_id, + frame_state.rg_builder, + RenderTargetKind::Color, + None, + original_size.to_i32(), + ); + + primary_render_task_id = blur_render_task_id; + + surface_descriptor = SurfaceDescriptor::new_chained( + picture_task_id, + blur_render_task_id, + surface_rects.clipped_local, + ); + } + PictureCompositeMode::Filter(Filter::DropShadows(ref shadows)) => { + let surface = &frame_state.surfaces[raster_config.surface_index.0]; + + let device_rect = surface_rects.clipped; + + let cmd_buffer_index = frame_state.cmd_buffers.create_cmd_buffer(); + + let picture_task_id = frame_state.rg_builder.add().init( + RenderTask::new_dynamic( + surface_rects.task_size, + RenderTaskKind::new_picture( + surface_rects.task_size, + surface_rects.needs_scissor_rect, + device_rect.min, + surface_spatial_node_index, + raster_spatial_node_index, + device_pixel_scale, + None, + None, + None, + cmd_buffer_index, + can_use_shared_surface, + ), + ).with_uv_rect_kind(surface_rects.uv_rect_kind) + ); + + let mut blur_tasks = BlurTaskCache::default(); + + self.extra_gpu_data_handles.resize(shadows.len(), GpuCacheHandle::new()); + + let mut blur_render_task_id = picture_task_id; + for shadow in shadows { + let (blur_radius_x, blur_radius_y) = surface.clamp_blur_radius( + shadow.blur_radius, + shadow.blur_radius, + ); + + blur_render_task_id = RenderTask::new_blur( + DeviceSize::new( + blur_radius_x * surface.local_scale.0 * device_pixel_scale.0, + blur_radius_y * surface.local_scale.1 * device_pixel_scale.0, + ), + picture_task_id, + frame_state.rg_builder, + RenderTargetKind::Color, + Some(&mut blur_tasks), + device_rect.size().to_i32(), + ); + } + + // Add this content picture as a dependency of the parent surface, to + // ensure it isn't free'd after the shadow uses it as an input. + frame_state.surface_builder.add_picture_render_task(picture_task_id); + + primary_render_task_id = blur_render_task_id; + self.secondary_render_task_id = Some(picture_task_id); + + surface_descriptor = SurfaceDescriptor::new_chained( + picture_task_id, + blur_render_task_id, + surface_rects.clipped_local, + ); + } + PictureCompositeMode::MixBlend(mode) if BlendMode::from_mix_blend_mode( + mode, + frame_context.fb_config.gpu_supports_advanced_blend, + frame_context.fb_config.advanced_blend_is_coherent, + frame_context.fb_config.dual_source_blending_is_supported, + ).is_none() => { + let parent_surface = &frame_state.surfaces[parent_surface_index.0]; + + // Create a space mapper that will allow mapping from the local rect + // of the mix-blend primitive into the space of the surface that we + // need to read back from. Note that we use the parent's raster spatial + // node here, so that we are in the correct device space of the parent + // surface, whether it establishes a raster root or not. + let map_pic_to_parent = SpaceMapper::new_with_target( + parent_surface.surface_spatial_node_index, + surface_spatial_node_index, + parent_surface.clipping_rect, + frame_context.spatial_tree, + ); + let pic_in_raster_space = map_pic_to_parent + .map(&pic_rect) + .expect("bug: unable to map mix-blend content into parent"); + + // Apply device pixel ratio for parent surface to get into device + // pixels for that surface. + let backdrop_rect = pic_in_raster_space; + let parent_surface_rect = parent_surface.clipping_rect; + + // If there is no available parent surface to read back from (for example, if + // the parent surface is affected by a clip that doesn't affect the child + // surface), then create a dummy 16x16 readback. In future, we could alter + // the composite mode of this primitive to skip the mix-blend, but for simplicity + // we just create a dummy readback for now. + + let readback_task_id = match backdrop_rect.intersection(&parent_surface_rect) { + Some(available_rect) => { + // Calculate the UV coords necessary for the shader to sampler + // from the primitive rect within the readback region. This is + // 0..1 for aligned surfaces, but doing it this way allows + // accurate sampling if the primitive bounds have fractional values. + + let backdrop_rect = parent_surface.map_to_device_rect( + &backdrop_rect, + frame_context.spatial_tree, + ); + + let available_rect = parent_surface.map_to_device_rect( + &available_rect, + frame_context.spatial_tree, + ).round_out(); + + let backdrop_uv = calculate_uv_rect_kind( + available_rect, + backdrop_rect, + ); + + frame_state.rg_builder.add().init( + RenderTask::new_dynamic( + available_rect.size().to_i32(), + RenderTaskKind::new_readback(Some(available_rect.min)), + ).with_uv_rect_kind(backdrop_uv) + ) + } + None => { + frame_state.rg_builder.add().init( + RenderTask::new_dynamic( + DeviceIntSize::new(16, 16), + RenderTaskKind::new_readback(None), + ) + ) + } + }; + + frame_state.surface_builder.add_child_render_task( + readback_task_id, + frame_state.rg_builder, + ); + + self.secondary_render_task_id = Some(readback_task_id); + + let task_size = surface_rects.clipped.size().to_i32(); + + let cmd_buffer_index = frame_state.cmd_buffers.create_cmd_buffer(); + + let render_task_id = frame_state.rg_builder.add().init( + RenderTask::new_dynamic( + task_size, + RenderTaskKind::new_picture( + task_size, + surface_rects.needs_scissor_rect, + surface_rects.clipped.min, + surface_spatial_node_index, + raster_spatial_node_index, + device_pixel_scale, + None, + None, + None, + cmd_buffer_index, + can_use_shared_surface, + ) + ).with_uv_rect_kind(surface_rects.uv_rect_kind) + ); + + primary_render_task_id = render_task_id; + + surface_descriptor = SurfaceDescriptor::new_simple( + render_task_id, + surface_rects.clipped_local, + ); + } + PictureCompositeMode::Filter(..) => { + let cmd_buffer_index = frame_state.cmd_buffers.create_cmd_buffer(); + + let render_task_id = frame_state.rg_builder.add().init( + RenderTask::new_dynamic( + surface_rects.task_size, + RenderTaskKind::new_picture( + surface_rects.task_size, + surface_rects.needs_scissor_rect, + surface_rects.clipped.min, + surface_spatial_node_index, + raster_spatial_node_index, + device_pixel_scale, + None, + None, + None, + cmd_buffer_index, + can_use_shared_surface, + ) + ).with_uv_rect_kind(surface_rects.uv_rect_kind) + ); + + primary_render_task_id = render_task_id; + + surface_descriptor = SurfaceDescriptor::new_simple( + render_task_id, + surface_rects.clipped_local, + ); + } + PictureCompositeMode::ComponentTransferFilter(..) => { + let cmd_buffer_index = frame_state.cmd_buffers.create_cmd_buffer(); + + let render_task_id = frame_state.rg_builder.add().init( + RenderTask::new_dynamic( + surface_rects.task_size, + RenderTaskKind::new_picture( + surface_rects.task_size, + surface_rects.needs_scissor_rect, + surface_rects.clipped.min, + surface_spatial_node_index, + raster_spatial_node_index, + device_pixel_scale, + None, + None, + None, + cmd_buffer_index, + can_use_shared_surface, + ) + ).with_uv_rect_kind(surface_rects.uv_rect_kind) + ); + + primary_render_task_id = render_task_id; + + surface_descriptor = SurfaceDescriptor::new_simple( + render_task_id, + surface_rects.clipped_local, + ); + } + PictureCompositeMode::MixBlend(..) | + PictureCompositeMode::Blit(_) => { + let cmd_buffer_index = frame_state.cmd_buffers.create_cmd_buffer(); + + let render_task_id = frame_state.rg_builder.add().init( + RenderTask::new_dynamic( + surface_rects.task_size, + RenderTaskKind::new_picture( + surface_rects.task_size, + surface_rects.needs_scissor_rect, + surface_rects.clipped.min, + surface_spatial_node_index, + raster_spatial_node_index, + device_pixel_scale, + None, + None, + None, + cmd_buffer_index, + can_use_shared_surface, + ) + ).with_uv_rect_kind(surface_rects.uv_rect_kind) + ); + + primary_render_task_id = render_task_id; + + surface_descriptor = SurfaceDescriptor::new_simple( + render_task_id, + surface_rects.clipped_local, + ); + } + PictureCompositeMode::IntermediateSurface => { + if !scratch.required_sub_graphs.contains(&pic_index) { + return None; + } + + // TODO(gw): Remove all the mostly duplicated code in each of these + // match cases (they used to be quite different). + let cmd_buffer_index = frame_state.cmd_buffers.create_cmd_buffer(); + + let render_task_id = frame_state.rg_builder.add().init( + RenderTask::new_dynamic( + surface_rects.task_size, + RenderTaskKind::new_picture( + surface_rects.task_size, + surface_rects.needs_scissor_rect, + surface_rects.clipped.min, + surface_spatial_node_index, + raster_spatial_node_index, + device_pixel_scale, + None, + None, + None, + cmd_buffer_index, + can_use_shared_surface, + ) + ).with_uv_rect_kind(surface_rects.uv_rect_kind) + ); + + primary_render_task_id = render_task_id; + + surface_descriptor = SurfaceDescriptor::new_simple( + render_task_id, + surface_rects.clipped_local, + ); + } + PictureCompositeMode::SvgFilter(ref primitives, ref filter_datas) => { + let cmd_buffer_index = frame_state.cmd_buffers.create_cmd_buffer(); + + let picture_task_id = frame_state.rg_builder.add().init( + RenderTask::new_dynamic( + surface_rects.task_size, + RenderTaskKind::new_picture( + surface_rects.task_size, + surface_rects.needs_scissor_rect, + surface_rects.clipped.min, + surface_spatial_node_index, + raster_spatial_node_index, + device_pixel_scale, + None, + None, + None, + cmd_buffer_index, + can_use_shared_surface, + ) + ).with_uv_rect_kind(surface_rects.uv_rect_kind) + ); + + let filter_task_id = RenderTask::new_svg_filter( + primitives, + filter_datas, + frame_state.rg_builder, + surface_rects.clipped.size().to_i32(), + surface_rects.uv_rect_kind, + picture_task_id, + device_pixel_scale, + ); + + primary_render_task_id = filter_task_id; + + surface_descriptor = SurfaceDescriptor::new_chained( + picture_task_id, + filter_task_id, + surface_rects.clipped_local, + ); + } + } + + let is_sub_graph = self.flags.contains(PictureFlags::IS_SUB_GRAPH); + + frame_state.surface_builder.push_surface( + raster_config.surface_index, + is_sub_graph, + surface_rects.clipped_local, + surface_descriptor, + frame_state.surfaces, + frame_state.rg_builder, + ); + + self.primary_render_task_id = Some(primary_render_task_id); + } + None => {} + }; + + let state = PictureState { + map_local_to_pic, + map_pic_to_world, + }; + + let mut dirty_region_count = 0; + + // If this is a picture cache, push the dirty region to ensure any + // child primitives are culled and clipped to the dirty rect(s). + if let Some(RasterConfig { composite_mode: PictureCompositeMode::TileCache { slice_id }, .. }) = self.raster_config { + let dirty_region = tile_caches[&slice_id].dirty_region.clone(); + frame_state.push_dirty_region(dirty_region); + dirty_region_count += 1; + } + + // Disallow subpixel AA if an intermediate surface is needed. + // TODO(lsalzman): allow overriding parent if intermediate surface is opaque + let subpixel_mode = match self.raster_config { + Some(RasterConfig { ref composite_mode, .. }) => { + let subpixel_mode = match composite_mode { + PictureCompositeMode::TileCache { slice_id } => { + tile_caches[&slice_id].subpixel_mode + } + PictureCompositeMode::Blit(..) | + PictureCompositeMode::ComponentTransferFilter(..) | + PictureCompositeMode::Filter(..) | + PictureCompositeMode::MixBlend(..) | + PictureCompositeMode::IntermediateSurface | + PictureCompositeMode::SvgFilter(..) => { + // TODO(gw): We can take advantage of the same logic that + // exists in the opaque rect detection for tile + // caches, to allow subpixel text on other surfaces + // that can be detected as opaque. + SubpixelMode::Deny + } + }; + + subpixel_mode + } + None => { + SubpixelMode::Allow + } + }; + + // Still disable subpixel AA if parent forbids it + let subpixel_mode = match (parent_subpixel_mode, subpixel_mode) { + (SubpixelMode::Allow, SubpixelMode::Allow) => { + // Both parent and this surface unconditionally allow subpixel AA + SubpixelMode::Allow + } + (SubpixelMode::Allow, SubpixelMode::Conditional { allowed_rect }) => { + // Parent allows, but we are conditional subpixel AA + SubpixelMode::Conditional { + allowed_rect, + } + } + (SubpixelMode::Conditional { allowed_rect }, SubpixelMode::Allow) => { + // Propagate conditional subpixel mode to child pictures that allow subpixel AA + SubpixelMode::Conditional { + allowed_rect, + } + } + (SubpixelMode::Conditional { .. }, SubpixelMode::Conditional { ..}) => { + unreachable!("bug: only top level picture caches have conditional subpixel"); + } + (SubpixelMode::Deny, _) | (_, SubpixelMode::Deny) => { + // Either parent or this surface explicitly deny subpixel, these take precedence + SubpixelMode::Deny + } + }; + + let context = PictureContext { + pic_index, + raster_spatial_node_index: frame_state.surfaces[surface_index.0].raster_spatial_node_index, + surface_spatial_node_index, + surface_index, + dirty_region_count, + subpixel_mode, + }; + + let prim_list = mem::replace(&mut self.prim_list, PrimitiveList::empty()); + + Some((context, state, prim_list)) + } + + pub fn restore_context( + &mut self, + pic_index: PictureIndex, + prim_list: PrimitiveList, + context: PictureContext, + prim_instances: &[PrimitiveInstance], + frame_context: &FrameBuildingContext, + frame_state: &mut FrameBuildingState, + ) { + // Pop any dirty regions this picture set + for _ in 0 .. context.dirty_region_count { + frame_state.pop_dirty_region(); + } + + if self.raster_config.is_some() { + frame_state.surface_builder.pop_surface( + pic_index, + frame_state.rg_builder, + frame_state.cmd_buffers, + ); + } + + if let Picture3DContext::In { root_data: Some(ref mut list), plane_splitter_index, .. } = self.context_3d { + let splitter = &mut frame_state.plane_splitters[plane_splitter_index.0]; + + // Resolve split planes via BSP + PicturePrimitive::resolve_split_planes( + splitter, + list, + &mut frame_state.gpu_cache, + &frame_context.spatial_tree, + ); + + // Add the child prims to the relevant command buffers + let mut cmd_buffer_targets = Vec::new(); + for child in list { + let child_prim_instance = &prim_instances[child.anchor.instance_index.0 as usize]; + + if frame_state.surface_builder.get_cmd_buffer_targets_for_prim( + &child_prim_instance.vis, + &mut cmd_buffer_targets, + ) { + let prim_cmd = PrimitiveCommand::complex( + child.anchor.instance_index, + child.gpu_address + ); + + frame_state.push_prim( + &prim_cmd, + child.anchor.spatial_node_index, + &cmd_buffer_targets, + ); + } + } + } + + self.prim_list = prim_list; + } + + /// Add a primitive instance to the plane splitter. The function would generate + /// an appropriate polygon, clip it against the frustum, and register with the + /// given plane splitter. + pub fn add_split_plane( + splitter: &mut PlaneSplitter, + spatial_tree: &SpatialTree, + prim_spatial_node_index: SpatialNodeIndex, + original_local_rect: LayoutRect, + combined_local_clip_rect: &LayoutRect, + world_rect: WorldRect, + plane_split_anchor: PlaneSplitAnchor, + ) -> bool { + let transform = spatial_tree + .get_world_transform(prim_spatial_node_index); + let matrix = transform.clone().into_transform().cast().to_untyped(); + + // Apply the local clip rect here, before splitting. This is + // because the local clip rect can't be applied in the vertex + // shader for split composites, since we are drawing polygons + // rather that rectangles. The interpolation still works correctly + // since we determine the UVs by doing a bilerp with a factor + // from the original local rect. + let local_rect = match original_local_rect + .intersection(combined_local_clip_rect) + { + Some(rect) => rect.cast(), + None => return false, + }; + let world_rect = world_rect.cast(); + + match transform { + CoordinateSpaceMapping::Local => { + let polygon = Polygon::from_rect( + local_rect.to_rect() * Scale::new(1.0), + plane_split_anchor, + ); + splitter.add(polygon); + } + CoordinateSpaceMapping::ScaleOffset(scale_offset) if scale_offset.scale == Vector2D::new(1.0, 1.0) => { + let inv_matrix = scale_offset.inverse().to_transform().cast(); + let polygon = Polygon::from_transformed_rect_with_inverse( + local_rect.to_rect().to_untyped(), + &matrix, + &inv_matrix, + plane_split_anchor, + ).unwrap(); + splitter.add(polygon); + } + CoordinateSpaceMapping::ScaleOffset(_) | + CoordinateSpaceMapping::Transform(_) => { + let mut clipper = Clipper::new(); + let results = clipper.clip_transformed( + Polygon::from_rect( + local_rect.to_rect().to_untyped(), + plane_split_anchor, + ), + &matrix, + Some(world_rect.to_rect().to_untyped()), + ); + if let Ok(results) = results { + for poly in results { + splitter.add(poly); + } + } + } + } + + true + } + + fn resolve_split_planes( + splitter: &mut PlaneSplitter, + ordered: &mut Vec<OrderedPictureChild>, + gpu_cache: &mut GpuCache, + spatial_tree: &SpatialTree, + ) { + ordered.clear(); + + // Process the accumulated split planes and order them for rendering. + // Z axis is directed at the screen, `sort` is ascending, and we need back-to-front order. + let sorted = splitter.sort(vec3(0.0, 0.0, 1.0)); + ordered.reserve(sorted.len()); + for poly in sorted { + let transform = match spatial_tree + .get_world_transform(poly.anchor.spatial_node_index) + .inverse() + { + Some(transform) => transform.into_transform(), + // logging this would be a bit too verbose + None => continue, + }; + + let local_points = [ + transform.transform_point3d(poly.points[0].cast_unit().to_f32()), + transform.transform_point3d(poly.points[1].cast_unit().to_f32()), + transform.transform_point3d(poly.points[2].cast_unit().to_f32()), + transform.transform_point3d(poly.points[3].cast_unit().to_f32()), + ]; + + // If any of the points are un-transformable, just drop this + // plane from drawing. + if local_points.iter().any(|p| p.is_none()) { + continue; + } + + let p0 = local_points[0].unwrap(); + let p1 = local_points[1].unwrap(); + let p2 = local_points[2].unwrap(); + let p3 = local_points[3].unwrap(); + let gpu_blocks = [ + [p0.x, p0.y, p1.x, p1.y].into(), + [p2.x, p2.y, p3.x, p3.y].into(), + ]; + let gpu_handle = gpu_cache.push_per_frame_blocks(&gpu_blocks); + let gpu_address = gpu_cache.get_address(&gpu_handle); + + ordered.push(OrderedPictureChild { + anchor: poly.anchor, + gpu_address, + }); + } + } + + /// Do initial checks to determine whether this picture should be drawn as part of the + /// frame build. + pub fn pre_update( + &mut self, + frame_context: &FrameBuildingContext, + ) { + // Resolve animation properties + self.resolve_scene_properties(frame_context.scene_properties); + } + + /// Called during initial picture traversal, before we know the + /// bounding rect of children. It is possible to determine the + /// surface / raster config now though. + pub fn assign_surface( + &mut self, + frame_context: &FrameBuildingContext, + parent_surface_index: Option<SurfaceIndex>, + tile_caches: &mut FastHashMap<SliceId, Box<TileCacheInstance>>, + surfaces: &mut Vec<SurfaceInfo>, + ) -> Option<SurfaceIndex> { + // Reset raster config in case we early out below. + self.raster_config = None; + + match self.composite_mode { + Some(ref composite_mode) => { + let surface_spatial_node_index = self.spatial_node_index; + + // Currently, we ensure that the scaling factor is >= 1.0 as a smaller scale factor can result in blurry output. + let mut min_scale; + let mut max_scale = 1.0e32; + + // If a raster root is established, this surface should be scaled based on the scale factors of the surface raster to parent raster transform. + // This scaling helps ensure that the content in this surface does not become blurry or pixelated when composited in the parent surface. + + let world_scale_factors = match parent_surface_index { + Some(parent_surface_index) => { + let parent_surface = &surfaces[parent_surface_index.0]; + + let local_to_surface = frame_context + .spatial_tree + .get_relative_transform( + surface_spatial_node_index, + parent_surface.surface_spatial_node_index, + ); + + // Since we can't determine reasonable scale factors for transforms + // with perspective, just use a scale of (1,1) for now, which is + // what Gecko does when it choosed to supplies a scale factor anyway. + // In future, we might be able to improve the quality here by taking + // into account the screen rect after clipping, but for now this gives + // better results than just taking the matrix scale factors. + let scale_factors = if local_to_surface.is_perspective() { + (1.0, 1.0) + } else { + local_to_surface.scale_factors() + }; + + let scale_factors = ( + scale_factors.0 * parent_surface.world_scale_factors.0, + scale_factors.1 * parent_surface.world_scale_factors.1, + ); + + scale_factors + } + None => { + let local_to_surface_scale_factors = frame_context + .spatial_tree + .get_relative_transform( + surface_spatial_node_index, + frame_context.spatial_tree.root_reference_frame_index(), + ) + .scale_factors(); + + let scale_factors = ( + local_to_surface_scale_factors.0, + local_to_surface_scale_factors.1, + ); + + scale_factors + } + }; + + // TODO(gw): For now, we disable snapping on any sub-graph, as that implies + // that the spatial / raster node must be the same as the parent + // surface. In future, we may be able to support snapping in these + // cases (if it's even useful?) or perhaps add a ENABLE_SNAPPING + // picture flag, if the IS_SUB_GRAPH is ever useful in a different + // context. + let allow_snapping = !self.flags.contains(PictureFlags::DISABLE_SNAPPING); + + // Check if there is perspective or if an SVG filter is applied, and thus whether a new + // rasterization root should be established. + let (device_pixel_scale, raster_spatial_node_index, local_scale, world_scale_factors) = match composite_mode { + PictureCompositeMode::TileCache { slice_id } => { + let tile_cache = tile_caches.get_mut(&slice_id).unwrap(); + + // We only update the raster scale if we're in high quality zoom mode, or there is no + // pinch-zoom active. This means that in low quality pinch-zoom, we retain the initial + // scale factor until the zoom ends, then select a high quality zoom factor for the next + // frame to be drawn. + let update_raster_scale = + !frame_context.fb_config.low_quality_pinch_zoom || + !frame_context.spatial_tree.get_spatial_node(tile_cache.spatial_node_index).is_ancestor_or_self_zooming; + + if update_raster_scale { + // Get the complete scale-offset from local space to device space + let local_to_device = get_relative_scale_offset( + tile_cache.spatial_node_index, + frame_context.root_spatial_node_index, + frame_context.spatial_tree, + ); + + tile_cache.current_raster_scale = local_to_device.scale.x; + } + + // We may need to minify when zooming out picture cache tiles + min_scale = 0.0; + + if frame_context.fb_config.low_quality_pinch_zoom { + // Force the scale for this tile cache to be the currently selected + // local raster scale, so we don't need to rasterize tiles during + // the pinch-zoom. + min_scale = tile_cache.current_raster_scale; + max_scale = tile_cache.current_raster_scale; + } + + // Pick the largest scale factor of the transform for the scaling factor. + let scaling_factor = world_scale_factors.0.max(world_scale_factors.1).max(min_scale).min(max_scale); + + let device_pixel_scale = Scale::new(scaling_factor); + + (device_pixel_scale, surface_spatial_node_index, (1.0, 1.0), world_scale_factors) + } + _ => { + let surface_spatial_node = frame_context.spatial_tree.get_spatial_node(surface_spatial_node_index); + + let enable_snapping = + allow_snapping && + surface_spatial_node.coordinate_system_id == CoordinateSystemId::root() && + surface_spatial_node.snapping_transform.is_some(); + + if enable_snapping { + let raster_spatial_node_index = frame_context.spatial_tree.root_reference_frame_index(); + + let local_to_raster_transform = frame_context + .spatial_tree + .get_relative_transform( + self.spatial_node_index, + raster_spatial_node_index, + ); + + let local_scale = local_to_raster_transform.scale_factors(); + + (Scale::new(1.0), raster_spatial_node_index, local_scale, (1.0, 1.0)) + } else { + // If client supplied a specific local scale, use that instead of + // estimating from parent transform + let world_scale_factors = match self.raster_space { + RasterSpace::Screen => world_scale_factors, + RasterSpace::Local(scale) => (scale, scale), + }; + + let device_pixel_scale = Scale::new(world_scale_factors.0.max(world_scale_factors.1)); + + (device_pixel_scale, surface_spatial_node_index, (1.0, 1.0), world_scale_factors) + } + } + }; + + let surface = SurfaceInfo::new( + surface_spatial_node_index, + raster_spatial_node_index, + frame_context.global_screen_world_rect, + &frame_context.spatial_tree, + device_pixel_scale, + world_scale_factors, + local_scale, + allow_snapping, + ); + + let surface_index = SurfaceIndex(surfaces.len()); + surfaces.push(surface); + + self.raster_config = Some(RasterConfig { + composite_mode: composite_mode.clone(), + surface_index, + }); + + Some(surface_index) + } + None => { + None + } + } + } + + /// Called after updating child pictures during the initial + /// picture traversal. Bounding rects are propagated from + /// child pictures up to parent picture surfaces, so that the + /// parent bounding rect includes any dynamic picture bounds. + pub fn propagate_bounding_rect( + &mut self, + surface_index: SurfaceIndex, + parent_surface_index: Option<SurfaceIndex>, + surfaces: &mut [SurfaceInfo], + frame_context: &FrameBuildingContext, + ) { + let surface = &mut surfaces[surface_index.0]; + + for cluster in &mut self.prim_list.clusters { + cluster.flags.remove(ClusterFlags::IS_VISIBLE); + + // Skip the cluster if backface culled. + if !cluster.flags.contains(ClusterFlags::IS_BACKFACE_VISIBLE) { + // For in-preserve-3d primitives and pictures, the backface visibility is + // evaluated relative to the containing block. + if let Picture3DContext::In { ancestor_index, .. } = self.context_3d { + let mut face = VisibleFace::Front; + frame_context.spatial_tree.get_relative_transform_with_face( + cluster.spatial_node_index, + ancestor_index, + Some(&mut face), + ); + if face == VisibleFace::Back { + continue + } + } + } + + // No point including this cluster if it can't be transformed + let spatial_node = &frame_context + .spatial_tree + .get_spatial_node(cluster.spatial_node_index); + if !spatial_node.invertible { + continue; + } + + // Map the cluster bounding rect into the space of the surface, and + // include it in the surface bounding rect. + surface.map_local_to_surface.set_target_spatial_node( + cluster.spatial_node_index, + frame_context.spatial_tree, + ); + + // Mark the cluster visible, since it passed the invertible and + // backface checks. + cluster.flags.insert(ClusterFlags::IS_VISIBLE); + if let Some(cluster_rect) = surface.map_local_to_surface.map(&cluster.bounding_rect) { + surface.unclipped_local_rect = surface.unclipped_local_rect.union(&cluster_rect); + } + } + + // If this picture establishes a surface, then map the surface bounding + // rect into the parent surface coordinate space, and propagate that up + // to the parent. + if let Some(ref mut raster_config) = self.raster_config { + // Propagate up to parent surface, now that we know this surface's static rect + if let Some(parent_surface_index) = parent_surface_index { + let surface_rect = raster_config.composite_mode.get_coverage( + surface, + Some(surface.unclipped_local_rect.cast_unit()), + ); + + let parent_surface = &mut surfaces[parent_surface_index.0]; + parent_surface.map_local_to_surface.set_target_spatial_node( + self.spatial_node_index, + frame_context.spatial_tree, + ); + + // Drop shadows draw both a content and shadow rect, so need to expand the local + // rect of any surfaces to be composited in parent surfaces correctly. + + if let Some(parent_surface_rect) = parent_surface + .map_local_to_surface + .map(&surface_rect) + { + parent_surface.unclipped_local_rect = + parent_surface.unclipped_local_rect.union(&parent_surface_rect); + } + } + } + } + + pub fn prepare_for_render( + &mut self, + frame_state: &mut FrameBuildingState, + data_stores: &mut DataStores, + ) -> bool { + let raster_config = match self.raster_config { + Some(ref mut raster_config) => raster_config, + None => { + return true + } + }; + + // TODO(gw): Almost all of the Picture types below use extra_gpu_cache_data + // to store the same type of data. The exception is the filter + // with a ColorMatrix, which stores the color matrix here. It's + // probably worth tidying this code up to be a bit more consistent. + // Perhaps store the color matrix after the common data, even though + // it's not used by that shader. + + match raster_config.composite_mode { + PictureCompositeMode::TileCache { .. } => {} + PictureCompositeMode::Filter(Filter::Blur { .. }) => {} + PictureCompositeMode::Filter(Filter::DropShadows(ref shadows)) => { + self.extra_gpu_data_handles.resize(shadows.len(), GpuCacheHandle::new()); + for (shadow, extra_handle) in shadows.iter().zip(self.extra_gpu_data_handles.iter_mut()) { + if let Some(mut request) = frame_state.gpu_cache.request(extra_handle) { + let surface = &frame_state.surfaces[raster_config.surface_index.0]; + let prim_rect = surface.clipped_local_rect.cast_unit(); + + // Basic brush primitive header is (see end of prepare_prim_for_render_inner in prim_store.rs) + // [brush specific data] + // [segment_rect, segment data] + let (blur_inflation_x, blur_inflation_y) = surface.clamp_blur_radius( + shadow.blur_radius, + shadow.blur_radius, + ); + + let shadow_rect = prim_rect.inflate( + blur_inflation_x * BLUR_SAMPLE_SCALE, + blur_inflation_y * BLUR_SAMPLE_SCALE, + ).translate(shadow.offset); + + // ImageBrush colors + request.push(shadow.color.premultiplied()); + request.push(PremultipliedColorF::WHITE); + request.push([ + shadow_rect.width(), + shadow_rect.height(), + 0.0, + 0.0, + ]); + + // segment rect / extra data + request.push(shadow_rect); + request.push([0.0, 0.0, 0.0, 0.0]); + } + } + } + PictureCompositeMode::Filter(ref filter) => { + match *filter { + Filter::ColorMatrix(ref m) => { + if self.extra_gpu_data_handles.is_empty() { + self.extra_gpu_data_handles.push(GpuCacheHandle::new()); + } + if let Some(mut request) = frame_state.gpu_cache.request(&mut self.extra_gpu_data_handles[0]) { + for i in 0..5 { + request.push([m[i*4], m[i*4+1], m[i*4+2], m[i*4+3]]); + } + } + } + Filter::Flood(ref color) => { + if self.extra_gpu_data_handles.is_empty() { + self.extra_gpu_data_handles.push(GpuCacheHandle::new()); + } + if let Some(mut request) = frame_state.gpu_cache.request(&mut self.extra_gpu_data_handles[0]) { + request.push(color.to_array()); + } + } + _ => {} + } + } + PictureCompositeMode::ComponentTransferFilter(handle) => { + let filter_data = &mut data_stores.filter_data[handle]; + filter_data.update(frame_state); + } + PictureCompositeMode::MixBlend(..) | + PictureCompositeMode::Blit(_) | + PictureCompositeMode::IntermediateSurface | + PictureCompositeMode::SvgFilter(..) => {} + } + + true + } +} + +fn get_transform_key( + spatial_node_index: SpatialNodeIndex, + cache_spatial_node_index: SpatialNodeIndex, + spatial_tree: &SpatialTree, +) -> TransformKey { + spatial_tree.get_relative_transform( + spatial_node_index, + cache_spatial_node_index, + ).into() +} + +/// A key for storing primitive comparison results during tile dependency tests. +#[derive(Debug, Copy, Clone, Eq, Hash, PartialEq)] +struct PrimitiveComparisonKey { + prev_index: PrimitiveDependencyIndex, + curr_index: PrimitiveDependencyIndex, +} + +/// Information stored an image dependency +#[derive(Debug, Copy, Clone, PartialEq, PeekPoke, Default)] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub struct ImageDependency { + pub key: ImageKey, + pub generation: ImageGeneration, +} + +impl ImageDependency { + pub const INVALID: ImageDependency = ImageDependency { + key: ImageKey::DUMMY, + generation: ImageGeneration::INVALID, + }; +} + +/// In some cases, we need to know the dirty rect of all tiles in order +/// to correctly invalidate a primitive. +#[derive(Debug)] +struct DeferredDirtyTest { + /// The tile rect that the primitive being checked affects + tile_rect: TileRect, + /// The picture-cache local rect of the primitive being checked + prim_rect: PictureRect, +} + +/// A helper struct to compare a primitive and all its sub-dependencies. +struct PrimitiveComparer<'a> { + prev_data: &'a [u8], + curr_data: &'a [u8], + prev_frame_id: FrameId, + curr_frame_id: FrameId, + resource_cache: &'a ResourceCache, + spatial_node_comparer: &'a mut SpatialNodeComparer, + opacity_bindings: &'a FastHashMap<PropertyBindingId, OpacityBindingInfo>, + color_bindings: &'a FastHashMap<PropertyBindingId, ColorBindingInfo>, +} + +impl<'a> PrimitiveComparer<'a> { + fn new( + prev: &'a TileDescriptor, + curr: &'a TileDescriptor, + resource_cache: &'a ResourceCache, + spatial_node_comparer: &'a mut SpatialNodeComparer, + opacity_bindings: &'a FastHashMap<PropertyBindingId, OpacityBindingInfo>, + color_bindings: &'a FastHashMap<PropertyBindingId, ColorBindingInfo>, + ) -> Self { + PrimitiveComparer { + prev_data: &prev.dep_data, + curr_data: &curr.dep_data, + prev_frame_id: prev.last_updated_frame_id, + curr_frame_id: curr.last_updated_frame_id, + resource_cache, + spatial_node_comparer, + opacity_bindings, + color_bindings, + } + } + + /// Check if two primitive descriptors are the same. + fn compare_prim( + &mut self, + prev_desc: &PrimitiveDescriptor, + curr_desc: &PrimitiveDescriptor, + ) -> PrimitiveCompareResult { + let resource_cache = self.resource_cache; + let spatial_node_comparer = &mut self.spatial_node_comparer; + let opacity_bindings = self.opacity_bindings; + let color_bindings = self.color_bindings; + + // Check equality of the PrimitiveDescriptor + if prev_desc != curr_desc { + return PrimitiveCompareResult::Descriptor; + } + + let mut prev_dep_data = &self.prev_data[prev_desc.dep_offset as usize ..]; + let mut curr_dep_data = &self.curr_data[curr_desc.dep_offset as usize ..]; + + let mut prev_dep = PrimitiveDependency::SpatialNode { index: SpatialNodeIndex::INVALID }; + let mut curr_dep = PrimitiveDependency::SpatialNode { index: SpatialNodeIndex::INVALID }; + + debug_assert_eq!(prev_desc.dep_count, curr_desc.dep_count); + + for _ in 0 .. prev_desc.dep_count { + prev_dep_data = peek_from_slice(prev_dep_data, &mut prev_dep); + curr_dep_data = peek_from_slice(curr_dep_data, &mut curr_dep); + + match (&prev_dep, &curr_dep) { + (PrimitiveDependency::Clip { clip: prev }, PrimitiveDependency::Clip { clip: curr }) => { + if prev != curr { + return PrimitiveCompareResult::Clip; + } + } + (PrimitiveDependency::SpatialNode { index: prev }, PrimitiveDependency::SpatialNode { index: curr }) => { + let prev_key = SpatialNodeKey { + spatial_node_index: *prev, + frame_id: self.prev_frame_id, + }; + let curr_key = SpatialNodeKey { + spatial_node_index: *curr, + frame_id: self.curr_frame_id, + }; + if !spatial_node_comparer.are_transforms_equivalent(&prev_key, &curr_key) { + return PrimitiveCompareResult::Transform; + } + } + (PrimitiveDependency::OpacityBinding { binding: prev }, PrimitiveDependency::OpacityBinding { binding: curr }) => { + if prev != curr { + return PrimitiveCompareResult::OpacityBinding; + } + + if let OpacityBinding::Binding(id) = curr { + if opacity_bindings + .get(id) + .map_or(true, |info| info.changed) { + return PrimitiveCompareResult::OpacityBinding; + } + } + } + (PrimitiveDependency::ColorBinding { binding: prev }, PrimitiveDependency::ColorBinding { binding: curr }) => { + if prev != curr { + return PrimitiveCompareResult::ColorBinding; + } + + if let ColorBinding::Binding(id) = curr { + if color_bindings + .get(id) + .map_or(true, |info| info.changed) { + return PrimitiveCompareResult::ColorBinding; + } + } + } + (PrimitiveDependency::Image { image: prev }, PrimitiveDependency::Image { image: curr }) => { + if prev != curr { + return PrimitiveCompareResult::Image; + } + + if resource_cache.get_image_generation(curr.key) != curr.generation { + return PrimitiveCompareResult::Image; + } + } + _ => { + // There was a mismatch between types of dependencies, so something changed + return PrimitiveCompareResult::Descriptor; + } + } + } + + PrimitiveCompareResult::Equal + } +} + +/// Details for a node in a quadtree that tracks dirty rects for a tile. +#[cfg_attr(any(feature="capture",feature="replay"), derive(Clone))] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub enum TileNodeKind { + Leaf { + /// The index buffer of primitives that affected this tile previous frame + #[cfg_attr(any(feature = "capture", feature = "replay"), serde(skip))] + prev_indices: Vec<PrimitiveDependencyIndex>, + /// The index buffer of primitives that affect this tile on this frame + #[cfg_attr(any(feature = "capture", feature = "replay"), serde(skip))] + curr_indices: Vec<PrimitiveDependencyIndex>, + /// A bitset of which of the last 64 frames have been dirty for this leaf. + #[cfg_attr(any(feature = "capture", feature = "replay"), serde(skip))] + dirty_tracker: u64, + /// The number of frames since this node split or merged. + #[cfg_attr(any(feature = "capture", feature = "replay"), serde(skip))] + frames_since_modified: usize, + }, + Node { + /// The four children of this node + children: Vec<TileNode>, + }, +} + +/// The kind of modification that a tile wants to do +#[derive(Copy, Clone, PartialEq, Debug)] +enum TileModification { + Split, + Merge, +} + +/// A node in the dirty rect tracking quadtree. +#[cfg_attr(any(feature="capture",feature="replay"), derive(Clone))] +#[cfg_attr(feature = "capture", derive(Serialize))] +#[cfg_attr(feature = "replay", derive(Deserialize))] +pub struct TileNode { + /// Leaf or internal node + pub kind: TileNodeKind, + /// Rect of this node in the same space as the tile cache picture + pub rect: PictureBox2D, +} + +impl TileNode { + /// Construct a new leaf node, with the given primitive dependency index buffer + fn new_leaf(curr_indices: Vec<PrimitiveDependencyIndex>) -> Self { + TileNode { + kind: TileNodeKind::Leaf { + prev_indices: Vec::new(), + curr_indices, + dirty_tracker: 0, + frames_since_modified: 0, + }, + rect: PictureBox2D::zero(), + } + } + + /// Draw debug information about this tile node + fn draw_debug_rects( + &self, + pic_to_world_mapper: &SpaceMapper<PicturePixel, WorldPixel>, + is_opaque: bool, + local_valid_rect: PictureRect, + scratch: &mut PrimitiveScratchBuffer, + global_device_pixel_scale: DevicePixelScale, + ) { + match self.kind { + TileNodeKind::Leaf { dirty_tracker, .. } => { + let color = if (dirty_tracker & 1) != 0 { + debug_colors::RED + } else if is_opaque { + debug_colors::GREEN + } else { + debug_colors::YELLOW + }; + + if let Some(local_rect) = local_valid_rect.intersection(&self.rect) { + let world_rect = pic_to_world_mapper + .map(&local_rect) + .unwrap(); + let device_rect = world_rect * global_device_pixel_scale; + + let outer_color = color.scale_alpha(0.3); + let inner_color = outer_color.scale_alpha(0.5); + scratch.push_debug_rect( + device_rect.inflate(-3.0, -3.0), + outer_color, + inner_color + ); + } + } + TileNodeKind::Node { ref children, .. } => { + for child in children.iter() { + child.draw_debug_rects( + pic_to_world_mapper, + is_opaque, + local_valid_rect, + scratch, + global_device_pixel_scale, + ); + } + } + } + } + + /// Calculate the four child rects for a given node + fn get_child_rects( + rect: &PictureBox2D, + result: &mut [PictureBox2D; 4], + ) { + let p0 = rect.min; + let p1 = rect.max; + let pc = p0 + rect.size() * 0.5; + + *result = [ + PictureBox2D::new( + p0, + pc, + ), + PictureBox2D::new( + PicturePoint::new(pc.x, p0.y), + PicturePoint::new(p1.x, pc.y), + ), + PictureBox2D::new( + PicturePoint::new(p0.x, pc.y), + PicturePoint::new(pc.x, p1.y), + ), + PictureBox2D::new( + pc, + p1, + ), + ]; + } + + /// Called during pre_update, to clear the current dependencies + fn clear( + &mut self, + rect: PictureBox2D, + ) { + self.rect = rect; + + match self.kind { + TileNodeKind::Leaf { ref mut prev_indices, ref mut curr_indices, ref mut dirty_tracker, ref mut frames_since_modified } => { + // Swap current dependencies to be the previous frame + mem::swap(prev_indices, curr_indices); + curr_indices.clear(); + // Note that another frame has passed in the dirty bit trackers + *dirty_tracker = *dirty_tracker << 1; + *frames_since_modified += 1; + } + TileNodeKind::Node { ref mut children, .. } => { + let mut child_rects = [PictureBox2D::zero(); 4]; + TileNode::get_child_rects(&rect, &mut child_rects); + assert_eq!(child_rects.len(), children.len()); + + for (child, rect) in children.iter_mut().zip(child_rects.iter()) { + child.clear(*rect); + } + } + } + } + + /// Add a primitive dependency to this node + fn add_prim( + &mut self, + index: PrimitiveDependencyIndex, + prim_rect: &PictureBox2D, + ) { + match self.kind { + TileNodeKind::Leaf { ref mut curr_indices, .. } => { + curr_indices.push(index); + } + TileNodeKind::Node { ref mut children, .. } => { + for child in children.iter_mut() { + if child.rect.intersects(prim_rect) { + child.add_prim(index, prim_rect); + } + } + } + } + } + + /// Apply a merge or split operation to this tile, if desired + fn maybe_merge_or_split( + &mut self, + level: i32, + curr_prims: &[PrimitiveDescriptor], + max_split_levels: i32, + ) { + // Determine if this tile wants to split or merge + let mut tile_mod = None; + + fn get_dirty_frames( + dirty_tracker: u64, + frames_since_modified: usize, + ) -> Option<u32> { + // Only consider splitting or merging at least 64 frames since we last changed + if frames_since_modified > 64 { + // Each bit in the tracker is a frame that was recently invalidated + Some(dirty_tracker.count_ones()) + } else { + None + } + } + + match self.kind { + TileNodeKind::Leaf { dirty_tracker, frames_since_modified, .. } => { + // Only consider splitting if the tree isn't too deep. + if level < max_split_levels { + if let Some(dirty_frames) = get_dirty_frames(dirty_tracker, frames_since_modified) { + // If the tile has invalidated > 50% of the recent number of frames, split. + if dirty_frames > 32 { + tile_mod = Some(TileModification::Split); + } + } + } + } + TileNodeKind::Node { ref children, .. } => { + // There's two conditions that cause a node to merge its children: + // (1) If _all_ the child nodes are constantly invalidating, then we are wasting + // CPU time tracking dependencies for each child, so merge them. + // (2) If _none_ of the child nodes are recently invalid, then the page content + // has probably changed, and we no longer need to track fine grained dependencies here. + + let mut static_count = 0; + let mut changing_count = 0; + + for child in children { + // Only consider merging nodes at the edge of the tree. + if let TileNodeKind::Leaf { dirty_tracker, frames_since_modified, .. } = child.kind { + if let Some(dirty_frames) = get_dirty_frames(dirty_tracker, frames_since_modified) { + if dirty_frames == 0 { + // Hasn't been invalidated for some time + static_count += 1; + } else if dirty_frames == 64 { + // Is constantly being invalidated + changing_count += 1; + } + } + } + + // Only merge if all the child tiles are in agreement. Otherwise, we have some + // that are invalidating / static, and it's worthwhile tracking dependencies for + // them individually. + if static_count == 4 || changing_count == 4 { + tile_mod = Some(TileModification::Merge); + } + } + } + } + + match tile_mod { + Some(TileModification::Split) => { + // To split a node, take the current dependency index buffer for this node, and + // split it into child index buffers. + let curr_indices = match self.kind { + TileNodeKind::Node { .. } => { + unreachable!("bug - only leaves can split"); + } + TileNodeKind::Leaf { ref mut curr_indices, .. } => { + curr_indices.take() + } + }; + + let mut child_rects = [PictureBox2D::zero(); 4]; + TileNode::get_child_rects(&self.rect, &mut child_rects); + + let mut child_indices = [ + Vec::new(), + Vec::new(), + Vec::new(), + Vec::new(), + ]; + + // Step through the index buffer, and add primitives to each of the children + // that they intersect. + for index in curr_indices { + let prim = &curr_prims[index.0 as usize]; + for (child_rect, indices) in child_rects.iter().zip(child_indices.iter_mut()) { + if prim.prim_clip_box.intersects(child_rect) { + indices.push(index); + } + } + } + + // Create the child nodes and switch from leaf -> node. + let children = child_indices + .iter_mut() + .map(|i| TileNode::new_leaf(mem::replace(i, Vec::new()))) + .collect(); + + self.kind = TileNodeKind::Node { + children, + }; + } + Some(TileModification::Merge) => { + // Construct a merged index buffer by collecting the dependency index buffers + // from each child, and merging them into a de-duplicated index buffer. + let merged_indices = match self.kind { + TileNodeKind::Node { ref mut children, .. } => { + let mut merged_indices = Vec::new(); + + for child in children.iter() { + let child_indices = match child.kind { + TileNodeKind::Leaf { ref curr_indices, .. } => { + curr_indices + } + TileNodeKind::Node { .. } => { + unreachable!("bug: child is not a leaf"); + } + }; + merged_indices.extend_from_slice(child_indices); + } + + merged_indices.sort(); + merged_indices.dedup(); + + merged_indices + } + TileNodeKind::Leaf { .. } => { + unreachable!("bug - trying to merge a leaf"); + } + }; + + // Switch from a node to a leaf, with the combined index buffer + self.kind = TileNodeKind::Leaf { + prev_indices: Vec::new(), + curr_indices: merged_indices, + dirty_tracker: 0, + frames_since_modified: 0, + }; + } + None => { + // If this node didn't merge / split, then recurse into children + // to see if they want to split / merge. + if let TileNodeKind::Node { ref mut children, .. } = self.kind { + for child in children.iter_mut() { + child.maybe_merge_or_split( + level+1, + curr_prims, + max_split_levels, + ); + } + } + } + } + } + + /// Update the dirty state of this node, building the overall dirty rect + fn update_dirty_rects( + &mut self, + prev_prims: &[PrimitiveDescriptor], + curr_prims: &[PrimitiveDescriptor], + prim_comparer: &mut PrimitiveComparer, + dirty_rect: &mut PictureBox2D, + compare_cache: &mut FastHashMap<PrimitiveComparisonKey, PrimitiveCompareResult>, + invalidation_reason: &mut Option<InvalidationReason>, + frame_context: &FrameVisibilityContext, + ) { + match self.kind { + TileNodeKind::Node { ref mut children, .. } => { + for child in children.iter_mut() { + child.update_dirty_rects( + prev_prims, + curr_prims, + prim_comparer, + dirty_rect, + compare_cache, + invalidation_reason, + frame_context, + ); + } + } + TileNodeKind::Leaf { ref prev_indices, ref curr_indices, ref mut dirty_tracker, .. } => { + // If the index buffers are of different length, they must be different + if prev_indices.len() == curr_indices.len() { + // Walk each index buffer, comparing primitives + for (prev_index, curr_index) in prev_indices.iter().zip(curr_indices.iter()) { + let i0 = prev_index.0 as usize; + let i1 = curr_index.0 as usize; + + // Compare the primitives, caching the result in a hash map + // to save comparisons in other tree nodes. + let key = PrimitiveComparisonKey { + prev_index: *prev_index, + curr_index: *curr_index, + }; + + let prim_compare_result = *compare_cache + .entry(key) + .or_insert_with(|| { + let prev = &prev_prims[i0]; + let curr = &curr_prims[i1]; + prim_comparer.compare_prim(prev, curr) + }); + + // If not the same, mark this node as dirty and update the dirty rect + if prim_compare_result != PrimitiveCompareResult::Equal { + if invalidation_reason.is_none() { + *invalidation_reason = Some(InvalidationReason::Content); + } + *dirty_rect = self.rect.union(dirty_rect); + *dirty_tracker = *dirty_tracker | 1; + break; + } + } + } else { + if invalidation_reason.is_none() { + *invalidation_reason = Some(InvalidationReason::PrimCount); + } + *dirty_rect = self.rect.union(dirty_rect); + *dirty_tracker = *dirty_tracker | 1; + } + } + } + } +} + +impl CompositeState { + // A helper function to destroy all native surfaces for a given list of tiles + pub fn destroy_native_tiles<'a, I: Iterator<Item = &'a mut Box<Tile>>>( + &mut self, + tiles_iter: I, + resource_cache: &mut ResourceCache, + ) { + // Any old tiles that remain after the loop above are going to be dropped. For + // simple composite mode, the texture cache handle will expire and be collected + // by the texture cache. For native compositor mode, we need to explicitly + // invoke a callback to the client to destroy that surface. + if let CompositorKind::Native { .. } = self.compositor_kind { + for tile in tiles_iter { + // Only destroy native surfaces that have been allocated. It's + // possible for display port tiles to be created that never + // come on screen, and thus never get a native surface allocated. + if let Some(TileSurface::Texture { descriptor: SurfaceTextureDescriptor::Native { ref mut id, .. }, .. }) = tile.surface { + if let Some(id) = id.take() { + resource_cache.destroy_compositor_tile(id); + } + } + } + } + } +} + +fn get_relative_scale_offset( + child_spatial_node_index: SpatialNodeIndex, + parent_spatial_node_index: SpatialNodeIndex, + spatial_tree: &SpatialTree, +) -> ScaleOffset { + let transform = spatial_tree.get_relative_transform( + child_spatial_node_index, + parent_spatial_node_index, + ); + let mut scale_offset = match transform { + CoordinateSpaceMapping::Local => ScaleOffset::identity(), + CoordinateSpaceMapping::ScaleOffset(scale_offset) => scale_offset, + CoordinateSpaceMapping::Transform(m) => { + ScaleOffset::from_transform(&m).expect("bug: pictures caches don't support complex transforms") + } + }; + + // Compositors expect things to be aligned on device pixels. Logic at a higher level ensures that is + // true, but floating point inaccuracy can sometimes result in small differences, so remove + // them here. + scale_offset.offset = scale_offset.offset.round(); + + scale_offset +} + +pub fn calculate_screen_uv( + p: DevicePoint, + clipped: DeviceRect, +) -> DeviceHomogeneousVector { + // TODO(gw): Switch to a simple mix, no bilerp / homogeneous vec needed anymore + DeviceHomogeneousVector::new( + (p.x - clipped.min.x) / (clipped.max.x - clipped.min.x), + (p.y - clipped.min.y) / (clipped.max.y - clipped.min.y), + 0.0, + 1.0, + ) +} + +fn get_surface_rects( + surface_index: SurfaceIndex, + composite_mode: &PictureCompositeMode, + parent_surface_index: SurfaceIndex, + surfaces: &mut [SurfaceInfo], + spatial_tree: &SpatialTree, + max_surface_size: f32, +) -> Option<SurfaceAllocInfo> { + let parent_surface = &surfaces[parent_surface_index.0]; + + let local_to_parent = SpaceMapper::new_with_target( + parent_surface.surface_spatial_node_index, + surfaces[surface_index.0].surface_spatial_node_index, + parent_surface.clipping_rect, + spatial_tree, + ); + + let local_clip_rect = local_to_parent + .unmap(&parent_surface.clipping_rect) + .unwrap_or(PictureRect::max_rect()) + .cast_unit(); + + let surface = &mut surfaces[surface_index.0]; + + let (clipped_local, unclipped_local) = match composite_mode { + PictureCompositeMode::Filter(Filter::DropShadows(ref shadows)) => { + let local_prim_rect = surface.clipped_local_rect; + + let mut required_local_rect = match local_prim_rect.intersection(&local_clip_rect) { + Some(rect) => rect, + None => return None, + }; + + for shadow in shadows { + let (blur_radius_x, blur_radius_y) = surface.clamp_blur_radius( + shadow.blur_radius, + shadow.blur_radius, + ); + let blur_inflation_x = blur_radius_x * BLUR_SAMPLE_SCALE; + let blur_inflation_y = blur_radius_y * BLUR_SAMPLE_SCALE; + + let local_shadow_rect = local_prim_rect + .translate(shadow.offset.cast_unit()); + + if let Some(clipped_shadow_rect) = local_clip_rect.intersection(&local_shadow_rect) { + let required_shadow_rect = clipped_shadow_rect.inflate(blur_inflation_x, blur_inflation_y); + + let local_clipped_shadow_rect = required_shadow_rect.translate(-shadow.offset.cast_unit()); + + required_local_rect = required_local_rect.union(&local_clipped_shadow_rect); + } + } + + let unclipped = composite_mode.get_rect(surface, None); + let clipped = required_local_rect; + + let clipped = match clipped.intersection(&unclipped.cast_unit()) { + Some(rect) => rect, + None => return None, + }; + + (clipped, unclipped) + } + _ => { + let surface_origin = surface.clipped_local_rect.min.to_vector().cast_unit(); + + let normalized_prim_rect = composite_mode + .get_rect(surface, None) + .translate(-surface_origin); + + let normalized_clip_rect = local_clip_rect + .cast_unit() + .translate(-surface_origin); + + let norm_clipped_rect = match normalized_prim_rect.intersection(&normalized_clip_rect) { + Some(rect) => rect, + None => return None, + }; + + let norm_clipped_rect = composite_mode.get_rect(surface, Some(norm_clipped_rect)); + + let norm_clipped_rect = match norm_clipped_rect.intersection(&normalized_prim_rect) { + Some(rect) => rect, + None => return None, + }; + + let unclipped = normalized_prim_rect.translate(surface_origin); + let clipped = norm_clipped_rect.translate(surface_origin); + + (clipped.cast_unit(), unclipped.cast_unit()) + } + }; + + let (mut clipped, mut unclipped) = if surface.raster_spatial_node_index != surface.surface_spatial_node_index { + assert_eq!(surface.device_pixel_scale.0, 1.0); + + let local_to_world = SpaceMapper::new_with_target( + spatial_tree.root_reference_frame_index(), + surface.surface_spatial_node_index, + WorldRect::max_rect(), + spatial_tree, + ); + + let clipped = (local_to_world.map(&clipped_local.cast_unit()).unwrap() * surface.device_pixel_scale).round_out(); + let unclipped = local_to_world.map(&unclipped_local).unwrap() * surface.device_pixel_scale; + + (clipped, unclipped) + } else { + let clipped = (clipped_local.cast_unit() * surface.device_pixel_scale).round_out(); + let unclipped = unclipped_local.cast_unit() * surface.device_pixel_scale; + + (clipped, unclipped) + }; + + let task_size_f = clipped.size(); + + if task_size_f.width > max_surface_size || task_size_f.height > max_surface_size { + let max_dimension = clipped_local.width().max(clipped_local.height()).ceil(); + + surface.raster_spatial_node_index = surface.surface_spatial_node_index; + surface.device_pixel_scale = Scale::new(max_surface_size / max_dimension); + + clipped = (clipped_local.cast_unit() * surface.device_pixel_scale).round(); + unclipped = unclipped_local.cast_unit() * surface.device_pixel_scale; + } + + let task_size = clipped.size().to_i32(); + debug_assert!(task_size.width <= max_surface_size as i32); + debug_assert!(task_size.height <= max_surface_size as i32); + + let uv_rect_kind = calculate_uv_rect_kind( + clipped, + unclipped, + ); + + // If the task size is zero sized, skip creation and drawing of it + if task_size.width == 0 || task_size.height == 0 { + return None; + } + + // If the final clipped surface rect is not the same or larger as the unclipped + // local rect of the surface, we need to enable scissor rect (which disables + // merging batches between this and other render tasks allocated to the same + // render target). This is conservative - we could do better in future by + // distinguishing between clips that affect the surface itself vs. clips on + // child primitives that don't affect this. + let needs_scissor_rect = !clipped_local.contains_box(&surface.unclipped_local_rect); + + Some(SurfaceAllocInfo { + task_size, + needs_scissor_rect, + clipped, + unclipped, + clipped_local, + uv_rect_kind, + }) +} + +fn calculate_uv_rect_kind( + clipped: DeviceRect, + unclipped: DeviceRect, +) -> UvRectKind { + let top_left = calculate_screen_uv( + unclipped.top_left().cast_unit(), + clipped, + ); + + let top_right = calculate_screen_uv( + unclipped.top_right().cast_unit(), + clipped, + ); + + let bottom_left = calculate_screen_uv( + unclipped.bottom_left().cast_unit(), + clipped, + ); + + let bottom_right = calculate_screen_uv( + unclipped.bottom_right().cast_unit(), + clipped, + ); + + UvRectKind::Quad { + top_left, + top_right, + bottom_left, + bottom_right, + } +} + +#[test] +fn test_large_surface_scale_1() { + use crate::spatial_tree::{SceneSpatialTree, SpatialTree}; + + let mut cst = SceneSpatialTree::new(); + let root_reference_frame_index = cst.root_reference_frame_index(); + + let mut spatial_tree = SpatialTree::new(); + spatial_tree.apply_updates(cst.end_frame_and_get_pending_updates()); + spatial_tree.update_tree(&SceneProperties::new()); + + let map_local_to_surface = SpaceMapper::new_with_target( + root_reference_frame_index, + root_reference_frame_index, + PictureRect::max_rect(), + &spatial_tree, + ); + + let mut surfaces = vec![ + SurfaceInfo { + unclipped_local_rect: PictureRect::max_rect(), + clipped_local_rect: PictureRect::max_rect(), + is_opaque: true, + clipping_rect: PictureRect::max_rect(), + map_local_to_surface: map_local_to_surface.clone(), + raster_spatial_node_index: root_reference_frame_index, + surface_spatial_node_index: root_reference_frame_index, + device_pixel_scale: DevicePixelScale::new(1.0), + world_scale_factors: (1.0, 1.0), + local_scale: (1.0, 1.0), + allow_snapping: true, + }, + SurfaceInfo { + unclipped_local_rect: PictureRect::new( + PicturePoint::new(52.76350021362305, 0.0), + PicturePoint::new(159.6738739013672, 35.0), + ), + clipped_local_rect: PictureRect::max_rect(), + is_opaque: true, + clipping_rect: PictureRect::max_rect(), + map_local_to_surface, + raster_spatial_node_index: root_reference_frame_index, + surface_spatial_node_index: root_reference_frame_index, + device_pixel_scale: DevicePixelScale::new(43.82798767089844), + world_scale_factors: (1.0, 1.0), + local_scale: (1.0, 1.0), + allow_snapping: true, + }, + ]; + + get_surface_rects( + SurfaceIndex(1), + &PictureCompositeMode::Blit(BlitReason::ISOLATE), + SurfaceIndex(0), + &mut surfaces, + &spatial_tree, + MAX_SURFACE_SIZE as f32, + ); +} |